Hydrothermally stable high pore volume aluminum oxide/swellable clay composites and methods of their preparation and use

ABSTRACT

Porous composite particles are provided which comprise an aluminum oxide component, e.g., crystalline boehmite, and a swellable clay component, e.g., synthetic hectorite, intimately dispersed within the aluminum oxide component at an amount effective to increase the hydrothermal stability, pore volume, and/or the mesopore pore mode of the composite particles relative to the absence of the swellable clay. Also provided is a method for making the composite particles, agglomerate particles derived therefrom, and a process for hydroprocessing petroleum feedstock using the agglomerates to support a hydroprocessing catalyst.

This is a division of application Ser. No. 09/482,734, filed Jan. 13,2000.

FIELD OF THE INVENTION

This invention relates to high pore volume aluminum oxide compositeparticles, methods of their production, agglomerates and supportedcatalysts derived therefrom; and methods of using said catalysts.

BACKGROUND OF THE INVENTION

The art relating to particulate porous alumina particles, shapedcatalyst supports derived therefrom, supports impregnated with variouscatalytically active metals, metal compounds and/or promoters, andvarious uses of such impregnated supports as catalysts, is extensive andrelatively well developed.

While the prior art shows a continuous modification and refinement ofsuch particles, supports, and catalysts to improve their catalyticactivity, and while in some cases highly desirable activities haveactually been achieved, there is a continuing need in the industry forimproved catalyst supports and catalysts derived therefrom. which haveenhanced activity and life mediated through a desirable balance ofmorphological properties.

Alumina is useful for a variety of applications including catalystsupports and catalysts for chemical processes, catalyst linings forautomotive mufflers, and the like. In many of these uses it will bedesirable to add catalytic materials, such as metallic ions,finely-divided metals, cations, and the like, to the alumina. The leveland distribution of these metals on the support, as well as theproperties of the support itself are key parameters that influence thecomplex nature of catalytic activity and life.

Alumina useful in catalytic applications has been produced heretofore bya variety of processes, such as the water hydrolysis of aluminumalkoxides, precipitation of alumina from alum, sodium aluminateprocesses, and the like. High costs arise from the latter two methodsbecause the quantity of by-products, such as sodium sulfate, actuallyexceed the quantity of desired product obtained, i.e., boehmite.Typically, the cost of boehmite will be 4 times as expensive as activealumina.

Generally speaking, while alumina from these sources can be used forcatalyst supports, such use is subject to certain limitations. Thisstems from the fact that for supported catalysts used in chemicalreactions, the morphological properties of the support, such as surfacearea, pore volume, and pore size distribution of the pores that comprisethe total pore volume are very important. Such properties areinstrumental in influencing the nature and concentration of activecatalytic sites, the diffusion of the reactants to the active catalystsite, the diffusion of products from the active sites, and catalystlife.

In addition, the support and its dimensions also influence themechanical strength, density and reactor packing characteristics, all ofwhich are important in commercial applications.

Hydroprocessing catalysts in petroleum refining represent a largesegment of alumina-supported catalysts in commercial use.Hydroprocessing applications span a wide range of feed types andoperating conditions, but have one or more of common objectives, namely,removal of heteroatom impurities (sulfur, nitrogen, oxygen, metals),increasing the H/C ratio in the products (thereby reducing aromatics,density and/or carbon residues), and cracking carbon bonds to reduceboiling range and average molecular weight.

More particularly, the use of a series of ebullated bed reactorscontaining a catalyst having improved effectiveness and activitymaintenance in the desulfurization and demetallation of metal-containingheavy hydrocarbon streams are well known.

As refiners increase the proportion of heavier, poorer quality crude oilin the feedstock to be processed, the need grows for processes to treatthe fractions containing increasingly higher levels of metals,asphaltenes, and sulfur.

It is widely known that various organometallic compounds and asphaltenesare present in petroleum crude oils and other heavy petroleumhydrocarbon streams, such as petroleum hydrocarbon residua, hydrocarbonstreams derived from tar sands, and hydrocarbon streams derived fromcoals. The most common metals found in such hydrocarbon streams arenickel, vanadium, and iron. Such metals are very harmful to variouspetroleum refining operations, such as hydrocracking,hydrodesulfurization. and catalytic cracking. The metals and asphaltenescause interstitial plugging of the catalyst bed and reduced catalystlife. The various metal deposits on a catalyst tend to poison ordeactivate the catalyst. Moreover, the asphaltenes tend to reduce thesusceptibility of the hydrocarbons to desulfurization. If a catalyst,such as a desulfurization catalyst or a fluidized cracking catalyst, isexposed to a hydrocarbon fraction that contains metals and asphaltenes,the catalyst will become deactivated rapidly and will be subject topremature replacement.

Although processes for the hydrotreating of heavy hydrocarbon streams,including but not limited to heavy crudes, reduced crudes, and petroleumhydrocarbon residua, are known, the use of fixed-bed catalytic processesto convert such feedstocks without appreciable asphaltene precipitationand reactor plugging and with effective removal of metals and othercontaminants, such as sulfur compounds and nitrogen compounds, are notcommon because the catalysts employed have not generally been capable ofmaintaining activity and performance.

Thus, certain hydroconversion processes are most effectively carried outin an ebullated bed system. In an ebullated bed, preheated hydrogen andresid enter the bottom of a reactor wherein the upward flow of residplus an internal recycle suspend the catalyst particles in the liquidphase. Recent developments involved the use of a powdered catalyst whichcan be suspended without the need for a liquid recycle. In this system,part of the catalyst is continuously or intermittently removed in aseries of cyclones and fresh catalyst is added to maintain activity.Roughly about 1 wt. % of the catalyst inventory is replaced each day inan ebullated bed system. Thus, the overall system activity is theweighted average activity of catalyst varying from fresh to very oldi.e., deactivated.

In general, it is desirable to design the catalyst for the highestsurface area possible in order to provide the maximum concentration ofcatalytic sites and activity. However, surface area and pore diameterare inversely related within practical limits. Sufficiently large poresare required for diffusion as the catalyst ages and fouls, but largepores have a lower surface area.

More specifically, the formulator is faced with competing considerationswhich often dictate the balance of morphological properties sought to beimparted to supports or catalysts derived therefrom.

For example, it is recognized (see for example. U.S. Pat. No. 4,497,909)that while pores having a diameter below 60 Angstroms (within the rangeof what is referred to herein as the micropore region) have the effectof increasing the number of active sites of certain silica/aluminahydrogenation catalysts, these very same sites are the first onesclogged by coke thereby causing a reduction in activity. Similarly, itis further recognized that when such catalysts have more than 10% of thetotal pore volume occupied by pores having a pore diameter greater than600 Angstroms (within the region referred to herein generally as themacropore region), the mechanical crush strength is lowered as is thecatalyst activity. Finally, it is recognized, for certain silica/aluminacatalysts, that maximization of pores having a pore diameter between 150and 600 Angstroms (approximately within the region referred to herein asthe mesopore region) is desirable for acceptable activity and catalystlife.

Thus, while increasing the surface area of the catalyst will increasethe number of the active sites, such surface area increase naturallyresults in an increase in the proportion of pores in the microporeregion. As indicated above, micropores are easily clogged by coke. Inshort, increases in surface area and maximization of mesopores areantagonistic properties.

Moreover, not only must the surface area be high, but it should alsoremain stable when exposed to conversion conditions such as hightemperature and moisture. There has therefore been a continuing searchfor high pore volume, high surface area, hydrothermally stable aluminasuitable for catalyst supports. The present invention was developed inresponse to this search.

U.S. Pat. No. 4,981,825 is directed to compositions of inorganic metaloxide (e.g., SiO₂) and clay particles wherein the oxide particles aresubstantially segregated from each other by the clay particles. Suitableclays include Laponite®. The disclosed ratio of metal oxide:clay isbetween 1:1 to 20:1 (preferably 4:1 to 10:1). The subject composition isderived from an inorganic oxide sol having a particle size of 40 to 800Angstroms (0.004 to 0.08 microns). The particle size of the finalproduct is dependent on the size of the particles in the starting sol,although the final particle size is unreported. It is critical that themetal oxide and clay particles have opposite charges so that they willbe attracted to each other such that the clay particles inhibitaggregation of the metal oxide particles. Thus, the clay particles aredescribed as being placed between the sol particles. Control of thecharges on the two different types of particles is determined by the pHof the sol. The pH of the inorganic oxide is controlled to be below itsisoelectric point by acid addition thereby inducing a positive charge onthe inorganic oxide particles. While suitable inorganic metal oxides aredisclosed to also include Al₂O₃, no examples of carrying out theinvention using Al₂O₃ are provided. Consequently, translating thisconcept to Al₂O₃ is not without difficulty. For example, the isoelectricpoint of Al₂O₃ is at a basic pH of about 9. However. Al₂O₃ sols onlyform at a low pH of less than about 5. If the pH exceeds about 5, anAl₂O₃ sol will precipitate from dispersion or never form in the firstplace. In contrast, SiO₂ sols do not have to be acidic. Consequently,while any point below the isoelectric point is acceptable for SiO₂ sols,the same is not true of Al₂O₃ sols. Rather, one must operate at a pHwell below the isoelectric point of the Al₂O₃ in the pH region wherealumina sols form. Moreover, this patent discloses nothing about thepore properties of the resulting composite and its thrust is onlydirected toward obtaining high surface area. As indicated above, surfacearea and high mesopore pore volume are typically antagonisticproperties.

In contrast, the presently claimed invention neither starts with anAl₂O₃ sol nor forms a sol during rehydration. The pH at which thepresently claimed composites are formed is too high for a sol to formduring rehydration and the starting alumina particles are too big for asol to form initially.

Another area of technology relating to combinations of various clay andmetal oxides is known as intercalated clays. Intercalated clays arerepresented by U.S. Pat. Nos. 3,803,026; 3,887,454 (See also U.S. Pat.No. 3,844,978); U.S. Pat. No. 3,892,655 (See also U.S. Pat. No.3,844,979); U.S. Pat. Nos. 4,637,992; 4,761,391 (See also U.S. Pat. No.4,844,790); and U.S. Pat. No. 4,995,964. Intercalated clay patentstypically have in common the requirement that large clay:sol ratios beemployed. Intercalated clays generally have most of their surface areain micropores unless freeze-dried.

U.S. Pat. No. 3,803,026 discloses a hydrogel or hydrogel slurrycomprising water, a fluorine-containing component, and an amorphouscogel comprising oxides or hydroxides of silicon and aluminum. Theamorphous cogel further comprises an oxide or hydroxide of at least oneelement selected from magnesium, zinc, boron, tin, titanium, zirconium,hafnium, thorium, lanthanum, cerium, praseodymium, neodymium, andphosphorus, said amorphous cogel being present in the hydrogel orhydrogel slurry at an amount of from 5 to 50 wt. %. The slurry issubjected to a pH of 6 to 10 and conversion conditions create asubstantial amount of crystalline aluminosilicate mineral, preferably inintimate admixture with a substantial amount of unreacted amorphouscogel. The silica/alumina molar ratio is at least 3:1 and the resultingmaterial is referred to as a synthetic layered crystalline clay-typealuminosilicate mineral and the unreacted amorphous co-gel exists mostlyas SiO₂. At column 5, lines 39 et seq., it is disclosed that theresulting aluminosilicate can be broken into particles, pulverized intoa powder, the powder dispersed in a hydrogel, or hydrogel slurry towhich is added components selected from precursor compounds of,inter-alia, alumina. The resulting mixture is then dried and activated.Notwithstanding the above disclosure, no specific examples employing amixture of silica-aluminate with alumina is disclosed. Consequently,neither the starting alumina, the final alumina, nor the amountsemployed of each material are disclosed.

U.S. Pat. No. 3,887,454 (and its parent U.S. Pat. No. 3,844,978)discloses a layered type dioctaliedral, clay-like mineral (LDCM)composed of silica, alumina, and having magnesia incorporated into itsstructure in controlled amounts. Preferred clays are montmorillonite andkaolin. At column 6, lines 24 et seq., it is disclosed that the claymaterial can be combined generally with inorganic oxide components suchas, interalia, amorphous alumina. In contrast, the presently claimedcomposite utilizes crystalline boehmite alumina. Similar disclosures arefound in U.S. Pat. Nos. 3.892,655: and 3,844,979, except that theselatter patents are directed to layer-type. trioctahedral, clay-likemineral containing magnesia as a component thereof (LTCM) andillustrated with a saponite type clay.

U.S. Pat. No. 4,637,992 is an intercalated clay patent which employscolloidal suspension of inorganic oxides and adds a swellable claythereto. While specific ranges illustrating the ratio of clay toinorganic oxide are not disclosed, it appears that the final material isstill referred to as being a clay based substrate into which isincorporated the inorganic oxide. Consequently, this suggests that thefinal material contains a major amount of clay rather than a predominateamount of aluminum oxide and very minor amounts of clay as in thepresent invention. See for example, column 5, lines 46 et seq., of the'992 patent.

U.S. Pat. No. 4,844,790 (division of U.S. Pat. No. 4,761,391) isdirected to a delaminated clay prepared by reacting a swellable claywith a pillaring agent which includes alumina. The ratio of clay topillaring agent is 0.1:1 to 10:1, preferably between 1:1 to 2:1. Theprimary thrust of the patent, however, is clay containing alumina andnot alumina containing less than 10 wt. % clay. It is reasoned that themetal oxides prop apart the platelets of the clay and impart aciditythereto which is responsible for the catalytic activity of thedelaminated clay. The preferred clay is a Laponite®.

U.S. Pat. No. 4,995,964, is directed to a product prepared byintercalating expandable clay (hectorite, saponite, montmorillonite)with oligimers derived from rare earth salts, and in particular,trivalent rare earths, and polyvalent cations of pillaring metals, suchas Al⁻³. The aluminum oxide material is an aluminum containing oligimerwhich is used in providing the pillars of the expanded clays. Theclaimed invention does not use or produce oligimers of aluminum hydroxymaterials.

U.S. Pat. No. 4,375,406 discloses compositions containing fibrous claysand precalcined oxides prepared by forming a fluid suspension of theclay with the precalcined oxide, agitating the suspension to form acodispersion, and shaping and drying the codispersion. The ratio offibrous formed clay to precalcined oxide composition can vary from 20:1to 1:5. These amounts are well above the amounts of clay employed in thepresently claimed invention. Moreover, fibrous clay is not within thescope of the swellable clays described herein.

A number of patents are directed to various types of alumina and methodsof making the same, namely, U.S. Pat. No. Re 29,605; SIR H198; and U.S.Pat. Nos. 3,322,495; 3,417,028; 3,773,691; 3,850,849; 3,898,322;3,974,099; 3,987,155; 4,045,331; 4,069,140; 4,073,718; 4,120,943;4,175,118; 4,708,945; 5,032,379; and 5,266,300.

More specifically, U.S. Pat. No. 3,974,099 is directed to silica/aluminahydrogels from sodium silicate and sodium aluminate cogels. The essenceof this invention is directed to the precipitation of Al₂O₃ ontosilica-alumina gel which stabilizes the cracking sites to hydrothermaldeactivation. (Column 2, lines 43 et seq.) The resulting materialtypically has about 38.6% alumina oxide when all the excess sodiumaluminate is removed. In contrast, the silica employed in the presentlyclaimed invention is an additive which coats the surface of thealumina/clay composite particles since it is added after the compositeformation.

U.S. Pat. No. 4,073,718 discloses a catalyst base of alumina stabilizedwith silica on which is deposited a cobalt or nickel catalyst.

U.S. Pat. No. 4,708,945 discloses a cracking catalyst of silicasupported on boehmite-like surface by compositing particles of porousboehmite and treating them with steam at greater than 500° C. to causesilica to react with the boehmite. 10% silica is usually used to achievea surface monolayer of silica to improve thermal stability.

U.S. Pat. No. 5,032,379 is directed to alumina having greater than 0.4cc/g pore volume and a pore diameter in the range of 30 to 200 Å. Thealumina is prepared by mixing two different types of rehydrationbondable aluminas to produce a product having a bimodal poredistribution.

U.S. Pat. No. 4,266,300 discloses an alumina support prepared by mixingat least two finely divided aluminas, each of which is characterized byat least one pore mode in at least one of the ranges (i) 100,000 to10,000 Å, (ii) 10,000 to 1,000 Å, (iii) 1,000 to 30 Å.

U.S. Pat. No. 4,791,090 discloses a catalyst support with a bidispersedmicropore size distribution. Column 4, lines 65, discloses that twosizes of micropores can be formulated by mixing completely differentmaterials having different pore sizes such as alumina and silica.

U.S. Pat. No. 4,497,909 is directed to silica/alumina carriers having asilica content less than about 40% by weight and at least one noblemetal component of Group VII of the Periodic Table and wherein thecatalyst contains pores having a diameter smaller than 600 Å occupyingat least 90% of the total pore volume, and pores having a diameter of150 to 600 Å occupying at least about 40% of the total pore volume madeup of pores having a diameter smaller than 600 Å.

The following patents disclose various types of clays: U.S. Pat. Nos.3,586,478; 4,049,780; 4,629,712; and PCT Publication Nos. WO 93/11069;and WO 94/16996.

The following patents disclose various types of agglomerates which canbe formed from alumina: U.S. Pat. Nos. 3,392,125: 3,630,888; 3,975,510;4,124,699; 4,276,201 (see also U.S. Pat. No. 4,309,278); U.S. Pat. Nos.4,392,987; and 5,244,648.

U.S. Pat. No. 4,276,201 discloses a hydroprocessing catalyst whichutilizes an agglomerate support of alumina, e.g., beaded alumina, andsilica wherein the silica is less than 10 wt. % of the support. Theagglomerate support has a surface area of 350-500 m²/g. A total porevolume (TPV) of 1.0 to 2.5 cc/g with less than 0.20 cc/g of the TPVresiding in pores having a diameter greater than 400 Å.

U.S. Pat. No. 5,114,895 discloses a composition of a layered clayhomogeneously dispersed in an inorganic oxide matrix such that the claylayers are completely surrounded by the inorganic oxide matrix. Theinorganic oxide matrix is selected from alumina, titania, silica,zirconia, P₂O₅ and mixtures. Suitable clays include bentonite,sepiolite, Laponite™, vermiculite, montmorillonite, kaolin, palygorskite(attapulgus), hectorite, chlorite, beidellite, saponite, and nontronite.To get the clay homogeneously dispersed within the inorganic oxidematrix, a precursor of the inorganic oxide is dispersed as a sol orhydrosol and gelled in the presence of the clay. While clay contents of5 to 70 wt. % are disclosed broadly, the Examples employ at least 30 wt.% clay. In addition, none of the pore properties or the resultingproduct are disclosed.

U.S. Pat. No. 4,159,969 discloses a process for the manufacture ofagglomerates of aluminum oxide by contacting a hydrous aluminum oxidegel with an organic liquid immiscible with water wherein the amount ofsaid liquid is a function of the water in the hydrous aluminum oxidegel. An amount of clay, such as bentonite or kaolin, sufficient toincrease the strength of the agglomerates may be added to the aluminumoxide during or after gelation. No specific amount of clay is disclosedand kaolin is not a swellable clay. None of the examples employ clay.

U.S. Pat. No. 3,630,888 discloses a catalyst having a structure in whichaccess channels having diameters between about 100 and 1000 Å unitsconstitute 10 to 40% of the total pore volume and in which accesschannels having diameters greater than 1000 Å units constitute betweenabout 10 to about 40% of the total pore volume, while the remainder ofthe pore volume comprises 20 to 80% of micropores with diameters lessthan 100 Å.

The following patents disclose various hydroprocessing operations anduse of catalysts therein: U.S. Pat. Nos. 3,887,455; 4,657,665;4,886,594: PCT Publication No. WO 95/31280.

SUMMARY OF THE INVENTION

The present invention is based on the discovery that when active aluminais dispersed and subjected to a rehydration process in the presence ofcontrolled amounts of a dispersed swellable clay, the resultingcomposite particles exhibit and maintain high surface area whilesimultaneously possessing a higher pore volume and pore mode in themesopore region relative to the absence of the clay. These propertiesare substantially preserved in agglomerates, e.g., shaped extrudates,derived from the composite particles before and after impregnation withcatalytically active metal components such as those employed forhydroprocessing operations. In addition, the incorporation of theswellable clay improves the hydrothermal stability of the compositeparticles.

Improvements in hydrothermal stability improve the overall economics ofa process employing the same while shifts to higher mesopore pore modesincrease the activity of supported catalyst derived from the compositeparticles. A higher pore mode improves accessibility of the hydrocarbonsand reduces the possibility of the pores being plugged due to coke ormetals deposition.

High pore volume aluminas are often prepared by azeotroping withalcohols to remove the water before drying. The alcohol is used toreduce the surface tension of the water which in turn reduces theshrinkage of pores during drying. This technique is very expensive andenvironmentally unfriendly. Aluminas with a high average pore diameter(APD) are often prepared by sintering at high temperatures. Whilesintering increases the APD of the unsintered material, it necessarilydecreases the surface area relative to the unsintered material. Thus,one is forced to sacrifice surface area in order to achieve the higherAPD. It has been found that one can not only shift the mesopore poremode to larger pores prior to sintering, but also it is believed thatless shrinkage in pore diameter will occur upon exposure to elevatedtemperatures(commonly associated with sintering without clay). Thus,since one can start with a higher pore mode, and less shrinkage occursfrom that higher pore mode, a high surface area, high pore volumeproduct can be obtained in a more cost efficient and environmentallyfriendly manner, e.g., alcohol azeotroping can be eliminated, and thetemperatures to which the alumina would otherwise need to be heated canbe lowered.

Accordingly, in one aspect of the present invention there is providedporous composite particles comprising an aluminum oxide component and aswellable clay component intimately dispersed within the aluminum oxidecomponent wherein in said composite particles:

(A) the alumina oxide component comprises at least 75 wt. % alumina, atleast 5 wt. % of which alumina is in the form of crystalline boehmite,gamma alumina derived from the crystalline boehmite, or mixturesthereof;

(B) the swellable clay component is dispersible prior to incorporationinto the composite particle and present in the composite particles at anamount (a) of less than about 10 wt. %, based on the combined weight ofthe aluminum oxide component and the swellable clay component. and (b)effective to increase at least one of the hydrothermal stability,nitrogen pore volume, and nitrogen mesopore pore mode of the compositeparticles relative to the corresponding hydrothermal stability, porevolume and mesopore pore mode, of the aluminum oxide component in theabsence of said swellable clay; and

(C) the average particle diameter of the composite particles is fromabout 0.1 to about 100 microns.

In a further aspect of the present invention, there is provided aprocess for making porous composite particles comprising:

(A) forming a non-colloidal dispersion comprising at least one aluminumoxide component comprising at least 75 wt. % active alumina, and atleast one swellable clay component in a liquid dispersing medium;

(B) rehydrating the active alumina of the aluminum oxide component inthe presence of said dispersed swellable clay to convert at least 5 wt.% of the active alumina to crystalline boehmite and to form compositeparticles comprising an effective amount of swellable clay intimatelydispersed within the aluminum oxide component, said effective amount ofswellable clay being (i) less than 10 wt. %, based on the combinedweight of the aluminum oxide component and swellable clay component, and(ii) sufficient to provide an increase in at least one of thehydrothermal stability, nitrogen pore volume and nitrogen mesopore poremode of the composite particles relative to the correspondinghydrothennal stability, pore volume, and mesopore pore mode, of thealuminum oxide component in the absence of said swellable clay;

(C) recovering the composite particles from the dispersion; and

(D) optionally calcining the recovered composite particles at atemperature of from about 250 to about 1,000° C. for a time of fromabout 0.15 to about 3 hours.

In another aspect of the present invention, there is providedagglomerates of the above particles.

In a further aspect of the present invention, there is providedsupported catalysts derived from the above agglomerates.

In a still further aspect of the present invention, there is provided aprocess for hydroprocessing petroleum feedstock using the aboveagglomerates as supports for hydroprocessing catalysts.

BRIEF DESCRIPTION OF THE DRAWINGS

The following table summarizes FIGS. 1 to 24 which are plots derivedfrom the examples. The pertinent information about the Figures includingthe corresponding Run Numbers, Example or Comparative Example Number,the X-axis, Y-axis and plot legends are provided in the following table:

Figure Summary Table Invention Disclosure Designation Attachment FigureRun Ex or C No. or Orig. No. Nos. Ex. No. X-Axis Y-Axis LegendDesignations Ref. No. Figure No. 1 1-2 Ex. 1 N₂ Pore Diameter A dV/d LogD Run 1 (0% L) 9433 A-2 Run 2 (2 wt. % L) 2 3-5 Ex. 2 N₂ Pore Diameter AdV/d Log D Run 3 (0% L) 9433 A-4 Run 4 (0.5 wt. % L) Run 5 (1 wt. % L) 33, 6, 7, 9, Ex. 2 N₂ Pore Diameter A dV/d Log D Run 1 (0% L) 9433 A-5 10Run 6 (2 wt. % L) Run 7 (3 wt. % L) Run 9 (5 wt. % L) Run 10 (6 wt. % L)4 16-1 Ex. 4 N₂ Pore Diameter A dV/d Log D Run 3 (0% wt. % L) 9433 A-716-2 Run 16-1 (3 wt. % SH-1) Run 16-2 (3 wt. % SH-2) 5 17-19 Ex. 5 N₂Pore Diameter A dV/d Log D Run 17 (0% L) 9433 A-8 Run 18 (4 wt. % NH-1)Run 19 (4 wt. % NH-2) 6 22-23 Ex. 6 wt. % L Steamed Run 22 (AP-15) 9433A-10 SA (m²/g) Run 23 (CP-3) 7 24-25 Ex. 7 wt. % L Steamed Run 24 (Posthydration) 9433 A-11 SA (m²/g) Run 25 (Pre hydration) 8 26-28 Ex. 8 N₂Pore Diameter A dV/d Log D Run 26 (0% L) 9433 A-13 Run 27 (3 wt. % L)Run 28 (3 wt. % L + milling) 9 32, 34, 35 C. Ex. 2 Pore Diameter A dV/dLog D Run 32 (0% Clay) 9433 A-16 Run 34 (6 wt. % CK) Run 35 (12 wt. %CK) 10 32, 36, 37 Ex. 10 N₂ Pore Diameter A dV/d Log D Run 32 (0 % Clay)9433 A-17 Run 36 (6 wt. % GL) Run 37 (12 wt. % GL) 11 32, 38, 39 Ex. 11N₂ Pore Diameter A dV/d Log D Run 32 (0 wt. % Clay) 9433 A-18 Run 39(0.5 wt. % SiO₂) Run 38 (1 wt. % SiO₂) 12 40-42 Ex. 12 Hrs @ 800° C. inSA Run 40 (0 wt. % L) 9433 A-19 contact with 20% Run 41 (3 wt. % L)steam Run 42 (3 wt. % L + milling) 13 40-42 Ex. 12 Hrs @ 800° C. in % SARetention Run 40 (0 % L) 9433 A-20 contact with 20% Run 41 (3 wt. % L)steam Run 42 (3 wt. % L + milling) 14 43-44 Ex. 13 Wt. % SiO₂ added toSteamed SA Run 43 (boehmite from CP-3) 9434 A-1 boehmite Run 44(boehmite from AP-15 ) 15 45-46 Ex. 14 Wt. % SiO₂added Steamed SA Run 45(3 wt. % L) 9434 A-2 Run 46 (5 wt. % L) 16 43-46 Ex. 14 Wt. % SiO₂ addedSteamed SA Run 43 (0% Clay) 9434 A-3 Run 44 (0% Clay) Run 45 (3 wt. %Clay) Run 46 (5 wt. % Clay) 17 47-49 Ex 15 Wt. % SiO₂ added Steamed SARun 47 (0% Clay) 9434 A-4 Run 48 (3 wt. % dispersed clay) Run 49 (3 wt.% poorly dispersed clay) 18 53-55 Ex. 17 Wt. % SiO₂ SA after 4 hours Run53 (SiO₂ After Age) 9434 A-6 @ 800° C. Run 54 (SiO₂ Before Age) Run 55(SiO₂ After Age @ 3 wt. % L) 19 56-59 Ex. 18 N₂ Pore Diameter A dV/d LogD Run 56 (0% SiO₂) 9434 A-7 Run 57 (2 wt. % SiO₂) Run 58 (4 wt. % SiO₂)Run 59 (8 wt. % SiO₂) 20 60-61 Ex. 19 Hg Pore Diameter A Hg dV/dLogD----- Run 61 (CAX-1) 9450 FIG. 1 - - - - - Run 60 (AX-1) 21 62, 64, 66,Ex. 20 Hg Pore Diameter A dV/dLogD ----- Run 68 (EMCAX-1) 9450 FIG. 2 68Ex. 21 - - - - - Run 62 (EMAX-1) C. Ex. 4 -- -- - Run 64 (EMAX-2) _____Run 66 (EMAX-3) 22 70-72 Ex. 23 Hg Pore Diameter A HgdV/dLogD ----- Run72 9450 FIG. 6 Ex. 24 - - - - - Run 71 C. Ex. 5 _____ Run 70 23 76-77Ex. 26 Catalyst Age, % Conversion ♦ Run 76 (EMAX-1) 9450 FIG. 9.1 C. Ex.7 bbl/lb. ▴ Run 77 (EMCAX-1) 24 78-80 Ex. 27 Catalyst Age, % Conversion♦ Run 78 (EMAX-2) 9450 FIG. 10.1 Ex. 28 bbl/lb. ▪ Run 79 (EMAX-3) C. Ex.8  Run 80 (EMCAX-1) dV/d log D = the differential of the change in porevolume (cc/g) per change in the differential of the Log of pore diameterL = Laponite ® (synthetic hectorite) CK = Calcined Kaolin GL = Gelwhite-I. Montmorillonite Clay SA = Surface Area

DESCRIPTION OF PREFERRED EMBODIMENTS

The term “micropore” as used herein means pores having a diameter ofless than 100 Angstroms.

The term “mesopore” as used herein means pores having a diameter between100 and 500 Angstroms.

The term “macropore” as used herein means pores having a diametergreater than 500 Angstroms.

The term “pore mode” as used herein means the pore diametercorresponding to the peak maximum where the log differential nitrogen ormercury intrusion in cc/g, is plotted as a function of the differentialof the log of the pore diameter.

The term “total pore volume” as used herein means the cumulative volumein cc/g of all pores discernable by either nitrogen desorption ormercury penetration methods. More specifically, for alumina particleswhich have not been agglomerated (e.g., by extrusion) the pore diameterdistribution and pore volume is calculated with reference to thenitrogen desorption isotherm (assuming cylindrical pores) by the B.E.T.technique as described by S. Brunauer, P. Emmett, and E. Teller in theJournal of American Chemical Society, 60, pp 209-319 (1939).

In respect to alumina particles which have been agglomerated, e.g.,formed into extrudates, the pore diameter distribution is calculated bymeans of the formula: $\begin{matrix}{{{Pore}\quad {Diameter}\quad \left( {{in}\quad {Anstroms}} \right)} = \frac{150}{{absolute}\quad {mercury}\quad {pressure}\quad \left( {{in}\quad {bar}} \right)}} & \left( {{Equation}\quad 1} \right)\end{matrix}$

and in accordance with the mercury penetration method (as described byH. L. Ritter and L. C. Drake in Industrial and Engineering Chemistry,Analytical Edition 17, 787 (1945)), using mercury pressures of 1-2000bar. Surface Area for composite particles as well as agglomerates isdetermined however by the nitrogen desorption method.

The total N₂ pore volume of a sample is the sum of the nitrogen porevolumes as determined by the above described nitrogen desorption method.Similarly, the total mercury pore volume of a sample is the sum of themercury pore volumes as determined by the mercury penetration methoddescribed above using a contact angle of 130°, a surface tension of 485dynes /cm and a Hg density of 13.5335 gm/cc.

All morphological properties involving weight, such as pore volume(cc/g) or surface area (m²/g) are to be normalized to a Metals FreeBasis as defined in accordance with Equation 4 described in Example 20.

All fresh surface areas are determined on samples which have been driedand then calcined in air at 537.8° C. for 2 hours.

Bulk density is measured by quickly transferring (in 10 seconds) thesample powder into a graduated cylinder which overflows when exactly 100cc is reached. No further powder is added at this point. . The rate ofpowder addition prevents settling within the cylinder. The weight of thepowder is divided by 100 cc to give the density.

All particle size and particle size distribution measurements describedherein are determined by a Mastersizer unit from Malvern, which operateson the principle of laser light diffraction and is known to all familiarin the art of small particle analysis.

The aluminum oxide component which is mixed with the swellable claycomponent comprises typically at least 75, preferably at least 80 (e.g.,at least 85). most preferably at least 90 (e.g., at least 95) wt. %active alumina which amounts can vary typically from about 75 to 100,preferably from about 80 to 100, and most preferably from about 90 to100 wt. % active alumina. Active alumina can be prepared by a variety ofmethods. For example, alumina trihydrate precipitated in the Bayerprocess may be ground and flash calcined. Active alumina, as referred toherein, is characterized as having a poorly crystalline and/or amorphousstructure.

The expression “alumina of poorly crystalline structure” for thepurposes of the aforegoing process is understood as meaning an aluminawhich is such that X-ray analysis gives a pattern which shows only oneor a few diffuse lines corresponding to the crystalline phases of thelow-temperature transition aluminas, and contains essentially the chi,rho, eta, gamma and pseudo-ganima phases and mixtures thereof.

By the expression “alumina of amorphous structure” is meant an aluminawhich is such that its X-ray analysis does not give any linecharacteristic of a highly (predominantly) crystalline phase.

Active alumina employed herein can be generally obtained by the rapiddehydration of aluminum hydroxides such as bayerite, hydrargillite orgibbsite, and nordstrandite, or of aluminum oxyhydroxides such asboehmite and diaspore. The dehydration can be carried out in anyappropriate apparatus, and by using a hot gaseous stream. Thetemperature at which the gases enter the apparatus can generally varyfrom about 400°to 1,200° C. and the contact time of the hydroxide oroxyhydroxide with the hot gases is generally between a fraction of asecond and 4 to 5 seconds.

The resulting product may contain minor, e.g., trace, amounts ofboehmite, gibbsite, gamma, alpha, delta and other crystalline aluminastructures.

The resulting active alumina will typically exhibit a weight loss whenheated to 538° C. for 1 hour of from about 4 to 12 wt. %.

The specific surface area of the active alumina obtained by the rapiddehydration of hydroxides or oxyhydroxides, as measured by theconventional BET method, generally varies between about 50 and 400 m²/g,and the diameter of the particles is generally between 0.1 and 300microns and preferably between 1 and 120 microns with an averageparticle size of typically greater than 1 micron, preferably betweenabout 5 and about 20, most preferably between about 5 and about 15microns. The loss on ignition, measured by calcination at 1,000° C.,generally varies between 3 and 15%, which corresponds to a molar ratioH₂O/Al₂O₃ of between about 0.17 and 1.0.

In a preferred embodiment, an active alumina originating from the rapiddehydration of Bayer hydrate (gibbsite), which is a readily availableand inexpensive industrial aluminum hydroxide is employed. Activealumina of this type is well known to those skilled in the art and theprocess for its preparation has been described, for example, in U.S.Pat. Nos. 2,915,365; 3,222,129; 4,579,839 and preferably U.S. Pat. No.4,051,072, column 3, line 6, to column 4, line 7, the disclosures ofwhich patents are incorporated herein by reference.

The active alumina employed can be used as such or may be treated sothat its sodium hydroxide content, expressed as Na₂O, is less than 1,000ppm.

More specifically, the composite particles prepared with silicate orcertain clays such as synthetic hectorite will typically contain Na₂O,which can cause sintering of the alumina at high temperatures. Thissintering will reduce surface area. To eliminate such sintering, thealumina is preferably washed to remove the Na₂O in the form of salts.Still, more specifically, the alumina is preferably slurried in watercontaining about 0.05 parts by weight ammonium sulfate (A/S), about 1part by weight alumina, and 5 parts by weight water, for 15 minutes. Theslurry is then filtered, washed at least one time with water to removesalts and oven dried. This wash can be conducted before or after contactwith the clay or on any component which may possess Na₂O. The activealumina employed may or may not be ground but it is preferred to beground to facilitate dispersion in or with the swellable clay slurrydescribed hereinafter.

Suitable active alumina powder starting material is commerciallyavailable from the Aluminum Company of America under grade designationsCP-3, CP-1, CP-5, CP-7, and CP-100 It is also available from Porocel(Little Rock, Ark.) under the designation AP-15.

All of the active aluminas suitable for use in the aluminum oxidecomponent of the present invention are rehydrateable and form a hydroxylbond upon contact with water. The present invention draws a distinctionbetween the phenomenon of rehydration, i.e., the chemical changesinduced by subjecting the active alumina to water and elevatedtemperatures, and the process of rehydration, i.e., the process stepsinvolved in inducing the phenomenon of rehydration.

The phenomenon of rehydration is believed to represent the chemical and,physical state of that active alumina which has been converted tocrystalline boehmite. However, the change in state from active aluminato boehmite does not have to be complete with reference to the entiresample being acted upon during the rehydration process. For example,depending on the condition of the rehydration process, it may bepossible that only the outer shell of an active alumina particle orfilter cake is converted to boehmite with the remaining inner portionsthereof remaining as either active alumina or some form of alumina otherthan boehmite or active alumina. Thus, while “rehydrated alumina” ischemically synonymous with boehmite; alumina derived from therehydration of active alumina includes boehmite, active alumina, and anyalumina by-products other than boehmite which might form during therehydration process. Similarly, the rehydration process refers to themanipulative process steps involving the addition of active alumina towater under conditions, e.g., elevated temperature, describedhereinafter.

The swellable clay component comprises any member of the 2:1clay:mineral layered silicate clays capable of undergoing swelling anddispersion and mixtures thereof. Swelling clays are expandable clayswhose platelets are held together by weak van der Waal's forces and havea particular shape or morphology. Such clays include the smectite classof clays as well as the ion exchanged (e.g., Na, Li⁺) derivativesthereof. In general, alkali metal exchange forms are preferred becauseof their enhanced ability to swell and disperse. Also, dispersible 2:1layered silicates such as tetrasilicic mica and taeniolite are useful.

More specifically, smectites are 2:1 clay mineral that carry a latticecharge and characteristically expand when solvated with water andalcohols, most notably ethylene glycol and glycerol. These mineralscomprise layers represented by the general formula:

 (M ₈)^(IV)(M′_(x))^(VI) O ₂₀(OH,F)₄

wherein IV indicates an ion coordinated to four other ions, VI indicatesan ion coordinated to six other ions and x may be 4 or 6. M is commonlySi⁴⁺. Al³⁺ and/or Fe³⁺, but also includes several other four coordinateions such as P⁵⁺, B³⁺, Ge⁴ ⁺, Be²⁺. and the like. M′ is commonly Al³⁺,or Mg²⁺, but also includes many possible hexacoordinated ions such asFe³⁺, Fe²⁺, Ni²⁺, Co²⁺, Li²⁺, and the like. The charge deficienciescreated by the various substitutions into these four and six coordinatecation positions are balanced by one or several cations located betweenthe structural units. Water may also be occluded between thesestructural units bonded either to the structure itself, or to thecations as a hydration shell. When dehydrated (dehydroxylated), theabove structural units have a repeat distance of about 9 to 12Angstroms, as measured by X-ray diffraction. Commercially availablenatural smectites include montmorillonite (bentonite), beidellite,hectorite, saponite, sauconite and nontronite. Also commerciallyavailable are synthetic smectites such as LAPONITE®, a synthetichectorite available from Laporte Industries Limited.

Smectites are classified into two categories, dioctahedral andtrioctahedral, the difference being the number of octahedral sites inthe central layer which are occupied. This, in turn, is related to thevalency of the cation in the central layers.

The dioctahedral smectites have central cations which are trivalent andaccordingly only two-thirds of the octahedral sites are occupied,whereas trioctahedral smectites have divalent central cations where allof the octahedral sites are occupied. Dioctahedral smectites includemontmorillonite, beidellite and nontronite wherein, for example,montmorillonite has as the octahedral cation (M′), aluminum, with othercations such as magnesium also present. Trioctahedral smectites, whichare preferred, include hectorite and saponite and their synthetic formswherein, for example. hectorite has as the octahedral cation (M′),magnesium, with lithium also present.

The smectite most advantageously used in the preparation of thecompositions of this invention is trioctahedral smectite clay having alath-shape morphology. However, trioctahedral smectites of platety-shapeor mixed lath-shape and platety-shape morphology can be employed.Exemplary of suitable trioctahedral smectite clays are natural saponite,and preferably, natural hectorite and synthetic hectorite.

The most preferred swelling clay for use as the swellable clay componentare the synthetic hectorites. Procedures for preparing synthetichectorites are well known and are described for example, in U.S. Pat.Nos. 3,803,026; 3,844,979; 3,887,454; 3,892,655 and 4,049,780, thedisclosures of which is herein incorporated by reference. A typicalexample of synthetic hectorite is Laponite® RD. Laponite® RD clay is afilter pressed, tray dried and pin milled product. The platelets ofLaponite® RD clay are composed of two silica layers surrounding a layerof magnesium in octahedral coordination, with lithium substitution inthis layer. Laponite® RD clay and other Laponites are manufactured andsold by Laporte Inorganics, a part of Laporte Industries Limited. Atypical analysis and the physical properties of Laponite® RD clay areset forth below in Table 1.

TABLE 1 Chemical Composition Laponite ® RD Component Weight % SiO₂ 59-60MgO 27-29 Li₂O 0.7-0.9 Na₂O 2.2-3.5 Loss of Ignition  8-10 PhysicalProperties Appearance white powder pH (2% Suspension) 9.8 Bulk Density(kg/m²) 1000 Surface Area (N₂ adsorption) 370 m²/g Sieve Analysis % <250 microns 98 Moisture Content, Wt. % 10

In order to prepare the composite particles of the present invention,non-colloidal active alumina is at least partially rehydrated in thepresence of the dispersed swellable clay.

Rehydration of the alumina will eventually naturally occur at roomtemperature in the presence of water but would take an extended amountof time. Rehydration is therefore preferably conducted at elevatedtemperatures of at least about 50° C. to speed up the rehydrationprocess. It is convenient to conduct rehydration by simple refluxing ofan aqueous slurry of the active alumina for a period of typically fromabout 1 to about 72, preferably from about 2 to about 48, and mostpreferably from about 3 to about 24 hours.

Rehydration conditions are controlled to obtain a high pore volumeproduct. Accordingly, rehydration conditions are controlled such thattypically at least 5, preferably at least 10, and most preferably atleast 15 wt. % of the active alumina is converted to boehmite, and theboehmite content in the alumina derived from the rehydration of activealumina can range typically from about 5 to about 100 (e.g., 30 to 100),preferably from about 10 to about 100 (e.g., 50 to 100), most preferablyfrom about 15 to about 100 (e.g., 75 to 100) wt. %, based on the weightof the alumina. An undesirable by-product to boehmite formation isbayerite which is an alumina trihydrate that forms if the pH of thewater exceeds about 10.

In view of the initial active alumina content in the aluminum oxidecomponent and the degree of conversion of active alumina to crystallineboehmite, the aluminum oxide component of the composite particles willdesirably contain (A) typically at least 75, preferably at least 80(e.g., at least 85), and most preferably at least 90 (e.g., at least 95)wt. % alumina, preferably alumina derived from the rehydration of activealumina, and (B) typically at least 3.75, and preferably at least 7.5,and most preferably at least 10 wt. % of the aluminum oxide component iscrystalline boehmite. which amount of crystalline boehmite can varytypically from about 3.75 to about 100 (e.g., 40-100), preferably fromabout 7.5 to about 100 (e.g., 75-100), and most preferably from about 10to about 100 (e.g., 90-100) wt. %, based on the weight of the aluminumoxide component. Similarly, the weight ratio of crystalline boehmite toswellable clay in the composite particles will typically vary from about4:1 to about 99:1, preferably from about 9:1 to about 50:1, and mostpreferably from about 15:1 to about 50:1.

The crystallite size (as determined by the procedure described atExample 1) will typically be less than about 110 (e.g., less than about100) Angstroms and will range typically from about 55 to about 110,preferably from about 60 to about 100, and most preferably from about 65to about 95 Angstroms.

Boehmite formation is maximized at a pH of about 9 (e.g., 7 to 10).Thus, a buffer, such as sodium gluconate, can be added to stabilize thepH at about 9 but such an additive can have the undesired effect ofreducing the size of the boehmite crystallites which in turn tends tolower the total pore volume. Thus, it is preferred not to employ abuffer. In fact, one of the advantages of the swellable clay is that itis a natural buffer at a pH of about 9 and inhibits rehydration toBayerite.

As indicated above, the rehydration of the active alumina in thealuminum oxide component must occur in the presence of the dispersedswellable clay. Without wishing to be bound to any particular theory, itis believed that the highly dispersed swellable clay becomes entrappedwithin the growing boehmite crystals and creates intercrystalline voidsby propping the crystallites apart, thereby increasing the pore volumewithout decreasing surface area. It is believed to be for this reasonthat the smaller the swellable clay particle size and the higher thedegree of dispersion of the clay particles in the slurry, the greaterwill be the shift of the pore mode in the mesopore region of thecomposite particles. The rehydration of the alumina neither starts withan alumina sol nor converts the active alumina to an alumina sol duringrehydration. Moreover, if the swellable clay is merely mixed withpreformed boehmite rather than forming the boehmite, e.g., byrehydration of active alumina, in the presence of the clay, the improvedpore properties will not be obtained.

In a preferred embodiment, the aluminum oxide component can be premilledprior to rehydration of the active alumina therein alone or in admixturewith the swellable clay. Premilling can be conducted in wet mills suchas DRAIS, PREMIER, or other types of sand or pebble mills.

However, if the premilling is conducted in the absence of the desiredswellable clay, it must be conducted under conditions, e.g., atsufficiently low temperatures, to avoid premature rehydration of thealumina before contact thereof with the dispersed swellable clay.

Premilling of the aluminum oxide component is conducted typically atroom temperature for a period sufficient to reduce the average particlesize to be typically from about 0.1 to about 8 (e.g., 1 to 8),preferably from about 0.1 to about 5 (e.g., 1 to 5), and most preferablyfrom about 0.1 to about 2.5 microns.

The swellable clay component is dispersed in a slurry, typically anaqueous slurry, under conditions which preferably will maximize thedegree of dispersion. Some swellable clays are more readily dispersiblethan others. If the degree of dispersion attained during contact withthe alumina being rehydrated is poor, the desired impact on the poreproperties of the alumina may not be attained or maximized. Accordingly,steps may need to be taken to induce the proper degree of dispersionsuch as milling, total volatiles control, and/or the use of dispersingaids such as tetrasodium pyrophosphate (Na₄P₂O₇). Slow addition of theclay to deionized water or water containing Na₄P₂O₇ to minimize theamount of divalent cations such as Ca⁺² and Mg⁺² helps to disperse theclay. The time required to disperse the clay is reduced if it is addedto a high shear mixer such as COWLES, MYERS or SILVERSON mixer.Satisfactory dispersion can be obtained with paddle type agitators,particularly when a tank with baffles is used.

Attainment of the proper degree of dispersion is difficult to quantify,but as a general rule, the greater the degree of clarity of thesuspending medium, the better the dispersion and a completely clearmedium is most preferred when employing a synthetic hectorite. This willtypically occur when the clay particles are predominately colloidal insize, e.g., less than about 1 micron.

Accordingly, dispersion of the swellable clay can be accomplished bymixing the clay with water, preferably under conditions of high shearfor periods of typically from about 5 to about 60, and preferably fromabout 10 to about 30 minutes. The temperature at which the dispersion isformed is not critical and will typically range from about 10 to about60° C. It is important that the water not contain other minerals, e.g.,deionized water is preferred, which would affect the dispersability ofthe clay.

The degree of dispersion is enhanced if the starting clay has a totalvolatile content of typically at least 6, and preferably at least 8 wt.% thereof, and can range typically from about 6 to about 30, preferablyfrom about 10 to about 20 and most preferably from about 12 to about 18wt. %.

The amount of clay sought to be imparted to the final compositeparticles is selected to be effective to increase at least one of thetotal nitrogen pore volume, hydrothermal stability, and/or the nitrogenmesopore pore mode relative to the corresponding pore volume,hydrothernal stability (as defined hereinafter) and mesopore pore modeof the aluminum oxide component in the absence of the swellable clay.More specifically, the mesopore pore mode is increased typically atleast 10, preferably at least 30, and most preferably at least 50% ofthe corresponding mesopore pore mode achieved in the absence of theswellable clay.

Suitable effective amounts of the swellable clay will typically be lessthan about 10 (e.g., less than about 9), preferably less than about 8,most preferably less than about 6 wt. %, and can vary typically fromabout 1 to about 9 (e.g., 1 to about 8). preferably from about 2 toabout 7, and most preferably from about 2 to about 5 wt. % based on thecombined weight of aluminum oxide component and swellable claycomponent.

As the clay content of the composite particles increases above 1 wt. %,not only is the mesopore pore volume increased, up until about 6 wt. %swellable clay, after which it begins to decrease, but also the surfacearea. In addition, the presence of the clay increases the hydrothermalstability of the composite particles up to about 10 w % clay content,after which it levels off or decreases.

From the above discussion, it will be apparent that rehydration of thealumina in the presence of the dispersed swellable clay can be broughtabout in a variety of ways.

For example, two separately prepared slurries (dispersions) containingthe swellable clay component and non-colloidal aluminum oxide component,respectively, can be combined or, preferably a single slurry can be madedirectly by adding either component first to water or simultaneouslycombining the clay and aluminum oxide components with water.

However, if two separate slurries are prepared care should be taken toassure that rehydration of the active alumina in the aluminum oxidecomponent does not occur prematurely before contact with the dispersedclay.

The solids content of the slurry containing the aluminum oxide componentand clay component is controlled such that it is typically from about 2to about 30, preferably from about 4 to about 25 and most preferablyfrom about 5 to about 25 wt. % based on the slurry weight. As the solidscontent decreases within these ranges, the mesopore pore mode willtypically increase and vice-versa when the clay wt. % is at or below 4.

Accordingly, absent premilling of the clay component and aluminum oxidecomponent, it is preferred to prepare a slurry of the dispersible claycomponent in dispersed form, add the aluminum oxide component theretoand then subject the mixture to shear under elevated temperature asdescribed above to intimately disperse the swellable oxide and rehydratethe alumina.

In one preferred embodiment, the dispersed clay component is premilledin admixture with the aluminum oxide component prior to rehydration ofthe alumina. Thus, in this embodiment, a slurry of the swellable claycomponent is prepared under agitation until fully dispersed. To the claydispersion is added the appropriate amount of aluminum oxide component,and the resultant combination wet milled, preferably severely milled, atroom temperature, e.g., in a DRAIS mill, for a period of typically fromabout 0.1 to about 3, preferably from about 0.5 to about 2.0 minutes.The premilled slurry is then refluxed as described above to rehydratethe alumina.

Premilling has been found to lead to increased hydrothermal stability ofthe composition while resulting in only a slight shift to smaller pores.

More specifically, the hydrothermal stability of the alumina compositeparticles is evaluated by comparing fresh and steamed surface areas asfollows.

The BET N₂ surface area is determined after calcining in air at 537.8°C. (1000° F.) for 2 hours and designated as the fresh surface area. Anuncalcined sample is then exposed to an atmosphere containing about 20 v% steam for 4 hours at 800° C. at autogenous pressure and BET surfacearea determined thereon and designated the steamed surface area.

A comparison is then made between the fresh and steamed surface areas.The smaller the difference between the fresh and steamed surface areas,the higher the hydrothermal stability.

Once rehydration of the active alumina (in the aluminum oxide component)in the presence of the swellable clay component is complete, theresulting composite particles can be recovered, thermally activatedunder the same conditions as described for agglomerates hereinafter orused directly to conduct application of catalyst thereto.

Preferably, the composite particles are recovered and dried andoptionally sized. Suitable particle sizes can range typically from about1 to about 150 (e.g., 1 to about 100), preferably from about 2 to about60, and most preferably from about 2 to about 50 microns.

Recovery is accomplished by filtration, evaporation, centrifugation andthe like. The slurry may also be spray dried to effect recovery.

The resulting composite particles have a nitrogen BET surface area (on ametals free basis) of typically at least about 200, preferably at leastabout 240, and most preferably at least about 260 m²/g, which surfacearea can range typically from about 200 to about 400, preferably fromabout 240 to about 350, and most preferably from about 240 to about 300m²/g. The surface area determination is made on a sample which has beendried at 138° C. (280° F.) for 8 hours and calcined for 2 hours at537.8° C. (1000° F.).

The average nitrogen pore diameter of the composite particles will rangetypically from about 60 to about 400 (e.g., 60 to about 300), preferablyfrom about 70 to about 275, and most preferably from about 80 to about250 Angstroms.

The total nitrogen pore volume of the composite particles (on a metalsfree basis) can vary from about 0.5 to about 2.0, preferably from about0.6 to about 1.8, and most preferably from about 0.7 to about 1.6 cc/g.Prior to testing for pore diameter or pore volume, the samples are ovendried at 138° C. (280° F.) and then calcined for 2 hours at 537.8° C.(1000° F.).

It is an advantage of the present invention that the swellable clayshifts the mesopore pore mode to a higher pore diameter relative to itsabsence while still maintaining a high surface area as recited above.

Even more importantly, the present invention provides a mechanism forcontrolling the size of the pore mode by varying the preparationconditions, particularly the clay content in the composite and thesolids content of the rehydration slurry. More specifically, reductionsin clay content from the optimum and/or increases in the rehydrationslurry solids content will each lower the pore mode.

Thus, the macropore content (i.e., % of those pores within the totalnitrogen pore volume which fall within the macropore region) of thecomposite particles will be typically not greater than about 40,preferably not greater than about 30, and most preferably not greaterthan about 25% of the total pore volume, which macropore content willrange typically from about 5 to about 50, preferably from about 10 toabout 40, and most preferably from about 10 to about 30% of the totalpore volume.

The nitrogen mesopore content will range typically from about 20 toabout 90, preferably from about 30 to about 80, and most preferably fromabout 40 to about 70% of the total pore volume. Moreover, typically atleast about 40, preferably at least about 50, and most preferably atleast about 60% of the pores within the mesopore region will have porediameters of typically from about 100 to about 400, preferably fromabout 100 to about 350, and most preferably from about 125 to about 300Angstroms.

The nitrogen mesopore content of the composite particles as formed alsodesirably will possess a nitrogen pore mode, preferably only a singlepore mode (monomodal), of typically from about 60 to about 400 (e.g. 60to about 300), preferably from about 70 to about 275, and mostpreferably from about 80 to about 250 Angstroms.

The nitrogen micropore content of the composite particles will betypically not greater than about 80, preferably not greater than about60, and most preferably not greater than about 50% of the total porevolume which micropore content can range typically from about 80 toabout 5, preferably from 60 about to about 10, and most preferably fromabout 30 to about 15% of the total pore volume.

It has been further found that the hydrothermal stability of thecomposite particles can be further improved by the incorporation ofsilicate salts therein.

Suitable silicate salts include the alkali and alkaline earth metalsilicates, most preferably sodium silicate. Less soluble silicates, suchas found in natural or synthetic clays or silica gels also improvestability. Examples of such clays are kaolinite, montmorillonite, andhectorite. Calcined clays also give improved hydrothermal stability.

The silicate can be added to the aluminum oxide and swellable claycomponents prior to rehydration, but it is preferred to conduct theaddition after rehydration (hot aging) to maximize the hydrothermalstability inducing effects, and to obtain a high pore volume and highaverage pore diameter. Addition of soluble silicate before rehydrationof the alumina tends to produce small pores which are somewhat lessstable (i.e., coalesce into larger pores upon heating) than large onesthereby reducing the total pore volume. The silicate can be added aftera few hours of hot aging after the pore size distribution is set.

Amounts of silicate effective to improve the hydrothermal stability ofthe composite particles described herein can range typically from about0.1 to about 40, preferably from about 1 to about 20, and mostpreferably from about 2 to about 10 wt. %, based on the combined weightof silicate, aluminum oxide component and swellable clay component.

Without wishing to be bound by any particular theory, it is believedthat the added silicate is distinguishable from the silicate in the clayin that the former is believed to be free to migrate to the aluminaduring rehydration whereas the clay silicate remains mostly intactduring rehydration. However, some of the observed effect of the clay onthe pore size and stability may be attributable to silicate migratedfrom the clay to the alumina during rehydration.

While the composite alumina particles can be used directly as supports,it is more conventional to agglomerate the particles for such use.

Such alumina agglomerates can be used as catalysts or catalyst supportsin any reaction which requires a particular pore structure together withvery good mechanical, thermal and hydrothermal properties. Theagglomerates of the present invention can thus find particularapplicability as catalyst supports in the treatment of exhaust gasesgenerated by internal combustion engines and in hydrogen treatments ofpetroleum products, such as hydrodesulfurization, hydrodemetallation andhydrodenitrification. They can also be used as catalyst supports inreactions for the recovery of sulfur compounds (Claus catalysis), thedehydration, reforming, steam reforming, dehydrohalogenation,hydrocracking, hydrogenation, dehydrogenation, and dehydrocyclization ofhydrocarbons or other organic compounds, as well as oxidation andreduction reactions. They can also be used as additives for fluidcracking catalysts, particularly to enhance pore volume and meso ormacroporosity.

They may also be used as catalysts per se in reactions typicallycatalyzed by aluminas such as hydrocracking and isomerization reactions.

Thus, the advantageous properties of enhanced mesopore content at highersurface area and hydrothermal stability of the composite particles arepassed on to the agglomerates.

The term “agglomerate” refers to a product that combines particles whichare held together by a variety of physical-chemical forces.

More specifically, each agglomerate is composed of a plurality ofcontiguous, constituent primary particles, sized as described above,preferably joined and connected at their points of contact.

Thus, the agglomerates of the present invention may exhibit a highermacropore content than the constituent primary particles because of theinterparticle voids between the constituent composite alumina particles.

Nevertheless, the agglomerate particles still preserve the highermesopore mode.

Accordingly, the agglomerates of the present invention are characterizedas having the following properties (on a metals free basis) after dryingfor 8 hours at 121° C. (250° F.) and calcination for 1 hour at 537.8° C.(1000° F.):

(1) a nitrogen surface area of at least about 100, preferably at leastabout 150, and most preferably from at least about 200 m²/g, whichsurface area can range typically about 100 to about 400, preferably fromabout 125 to about 375, and most preferably from about 150 to about 350m²/g,

(2) a bulk density of the agglomerates of typically at least about 0.30,preferably at least about 0.35, and most preferably at least about 0.40g/ml which bulk density can range typically from about 0.30 to about 1,preferably from about 0.35 to about 0.95, and most preferably from about0.40 to about 0.90 g/ml.

(3) a total mercury pore volume of from about 0.40 to about 2.0,preferably from about 0.5 to about 1.8, and most preferably from about0.6 to about 1.5 cc/g,

(4) a macropore content (i.e., those pores within the total pore volumewhich fall within the macropore region) of typically not greater thanabout 40, preferably not greater than about 30, and most preferably notgreater than about 20%, of the total pore volume, which macroporecontent will range typically from about 5 to about 40, preferably fromabout 10 to about 35, and most preferably from about 15 to about 30% ofthe total pore volume,

(5) a mesopore content of typically from about 15 to about 95,preferably from about 20 to about 90, and most preferably from about 30to about 80% of the total pore volume. Moreover, typically at leastabout 30, preferably at least about 40, and most preferably at leastabout 50% of the pores within the mesopore region will have porediameters of typically from about 80 to about 400 (e.g., 100 to 400),preferably from about 90 to about 350 (e.g., 100 to 350), and mostpreferably from about 105 to about 300 Angstroms,

(6) an average agglomerate particle diameter of typically from about 0.5to about 5, preferably from about 0.6 to about 2, and most preferablyfrom about 0.8 to 1.5 mm.

The mesopore content of the agglomerate particles as calcined alsodesirably will possess a mesopore pore mode of typically from about 60to about 400 (e.g., 60 to about 300), preferably from about 65 to about275, and most preferably from about 70 to about 250 Angstroms.

In addition, the agglomerates may be mixed with other conventionalaluminas to produce supports having a pore size distribution with two ormore modes in the mesopore region. Each alumina contributes a mesoporemode at its unique characteristic position. Mixtures of two or morealuminas prepared with the swellable clays having varying pore modes arealso contemplated.

The agglomeration of the alumina composite is carried out in accordancewith the methods well known to the art, and, in particular, by suchmethods as pelletizing, extrusion, shaping into beads in a rotatingcoating drum, and the like. The nodulizing technique whereby compositeparticles having a diameter of not greater than about 0.1 mm areagglomerated to particles with a diameter of at least about 1 mm bymeans of a granulation liquid may also be employed.

As is known to those skilled in the art, the agglomeration mayoptionally be carried out in the presence of additional amorphous orcrystalline binders, and pore-forming agents may be added to the mixtureto be agglomerated. Conventional binders include other forms of alumina,silica, silica-alumina, clays, zirconia, silica-zirconia, magnesia andsilica-boria. Conventional pore-forming agents which can be used inparticular, include wood flour, wood charcoal, cellulose, starches,naphthalene and, in general, all organic compounds capable of beingremoved by calcination. The addition of pore forming agents, however, isnot necessary or desirable.

If necessary, the aging, drying and/or calcination of the agglomeratesare then carried out.

The agglomerates, once formed, are then typically subjected to a thermalactivation treatment at a temperature in the range of typically fromabout 250 to about 1000, preferably from about 350 to about 900, andmost preferably from about 400 to about 800° C. for periods of typicallyfrom about 0.15 to about 3.0, preferably from about 0.33 to about 2.0,and most preferably from about 0.5 to about 1 hour(s). The atmosphere ofactivation is typically air, but can include inert gases such asnitrogen or stearn.

The activation treatment can be carried out in several steps if desiredor be part of the agglomerate treatment. Depending on the particularactivation temperature and time employed, the alumina agglomeratespredominantly exhibit the crystal structure characteristic of boehmite,or gamma alumina, or mixtures thereof.

More specifically, at calcination temperatures and times increasinglyabove about 300° C. and one hour, the boehmite will be increasinglyconverted to gamma alumina. However, the gamma alumina will possess thepore properties of the boehmite from which it is derived. Moreover, atthe preferred calcination temperatures and times substantially all ofthe crystalline boehmite is converted to gamma alumina. Consequently,the sum of the crystalline boehmite content (wt. %) discussed above plusthe gamma alumina content resulting from calcination of the boehmite,will not typically exceed the original boehmite content derived fromrehydration of the active alumina. This conclusion applies equally tocomposite particles which are activated and used directly in compositeparticle form without agglomeration.

The percent γ-Al₂O₃ (gamma alumina) is determined as follows:

(1) 100% γ-Al₂O₃ is defined as an integrated intensity (area under thepeak) of the (440) peak of a γ-Al₂O₃ standard.

(2) The (101) peak intensity of a Quartz plate is used as an X-rayintensity monitor.

(3) Data collection is performed on a Philips® 3720 automaticdiffractometer equipped with a graphite diffract beam monochromator andsealed Cu X-Ray tube. The X-ray generator is operated at 45 kV and 40mA.

(4) Full width at half maximum (FWHM) and integrated intensity (areaunder the peak) of the (440) γ-Al₂O₃ peak are obtained by curve fitting.In the case where one peak can not yield a good fit of the peak, twopeaks are used. In the case where two peaks are used for curve fitting,two crystallite sizes are obtained by using Equation 3. Percent γ-Al₂O₃of the two crystallite sizes are obtained by using Equation 2.

(5) The percentage of γ-Al₂O₃ of a sample is determined by the followingequation:

%_(γ-Al2O3)=(I _(sample) *I _(quartz.c))/(I _(standard) *I_(quartz.s))  (Equation 2)

wherein:

I_(sample)=Integrated intensity of the (440) peak of sample;

I_(quartz.c)=Intensity of the (101) quartz peak, measured at the timethat the standard γ-Al₂O₃ is measured;

I_(standard)=Integrated intensity of the (440) peak of the standardγ-Al₂O₃; and

I_(quartz.s)=Intensity of the (101) quartz peak, measured at the timethe sample is measured.

γ-Al₂O₃ crystallite size (L) is determined by the following procedure.The sample is hand ground with a mortar and pestle. An even layer of thesample is placed on 3.5 gms polyvinyl alcohol (PVA) and pressed for 10seconds at 3,000 psi to obtain a pellet. The pellet is then scanned withCu K Alpha radiation and the diffraction pattern between 63 and 73degrees (2θ) is plotted. The peak at 66.8 degrees (2θ) is used tocalculate the crystallite size using Equation 3 and the measured peakwidth at half height.

L(size in Å)=82.98/FWHM(2θ°) cos (θ°)  (Equation 3)

wherein:

FWHM=Full width at half maximum; and

θ=The angle of diffraction between X-ray beam and planar surface onwhich the sample is sitting.

The percent boehmite is determined as described at Example 1.

The large average pore diameter and high pore volume render the aluminacomposites of the present invention useful for the treatment of: highmolecular weight, high boiling feeds, where not all the feed can bepractically vaporized, in both F.C.C. and hydroprocessing operations;short contact time cracking operations, where the large pores canminimize diffusion resistance; hydrocracking, hydrotreating,hydro-desulfurization and hydro denitrogenation; processing of tarsands, shale oil extracts or coal liquids; catalyst supports withmetals, the high pore volume and pore diameter providing for improvedmetal dispersion; separation of high molecular weight compounds in asolvent from lower molecular weight compounds: and applicationsrequiring fine particle size aluminas at low pH, such as in suspendingagents, and polishing agents.

The alumina composite particles are particularly adapted for use assupports for a variety of catalyst systems employing heavy metals as thecatalyst component. Consequently, the metal components of such catalystsmust be added and incorporated into the alumina composite. Thermalactivation is typically conducted after agglomerate formation ratherthan before.

Such additions can be achieved by mixing the catalytic materials withthe alumina during the production of the composite alumina but afterrehydration thereof. during the preparation of the agglomerates, e.g.extrudates or pellets and the like, by impregnating the aluminaagglomerates, such as extrudates or pellets, with catalytic material byimmersion in solutions containing the catalytic material and the like.The “dry” impregnation technique is another suitable alternative whereinthe composite particles or agglomerates are contacted with a quantity ofimpregnation liquid, the volume of which corresponds to the pore volumeof the support. Other and additional methods of modifying the aluminamay appear desirable to those skilled in the art.

The porous composite aluminas of the present invention are particularlyuseful when employed as supports for catalytically active hydrogenationcomponents such as Group VIB and Group VIII metals. These catalyticallyactive materials can be suitably applied in hydroprocessing operations.

More specifically, “hydroprocessing” as the term is employed hereinmeans oil refinery processes for reacting petroleum feedstocks (complexmixtures of hydrocarbon present in petroleum which are liquid atconditions of standard temperature and pressure) with hydrogen underpressure in the presence of a catalyst to lower: (a) the concentrationof at least one of sulfur, contaminant metals, nitrogen. and Conradsoncarbon, present in said feedstock, and (b) at least one of theviscosity. pourpoint, and density of the feedstock. Hydroprocessingincludes hydrocracking, isomerization/dewaxing, hydrofinishing, andhydrotreating processes which differ by the amount of hydrogen reactedand the nature of the petroleum feedstock treated.

Hydrofinishing is typically understood to involve the hydroprocessing ofhydrocarbonaceous oil containing predominantly (by weight of)hydrocarbonaceous compounds in the lubricating oil boiling range(“feedstock”) wherein the feedstock is contacted with solid supportedcatalyst at conditions of elevated pressure and temperature for thepurpose of saturating aromatic and olefinic compounds and removingnitrogen, sulfur, and oxygen compounds present within the feedstock, andto improve the color, odor, thermal, oxidation, and UV stability,properties of the feedstock.

Hydrocracking is typically understood to involve the hydroprocessing ofpredominantly hydrocarbonaceous compounds containing at least five (5)carbon atoms per molecule (“feedstock”) which is conducted: (a) atsuperatmospheric hydrogen partial pressure; (b) at temperaturestypically below 593.3° C. (1100° F.); (c) with an overall net chemicalconsumption of hydrogen; (d) in the presence of a solid supportedcatalyst containing at least one (1) hydrogenation component; and (e)wherein said feedstock typically produces a yield greater than about onehundred and thirty (130) moles of hydrocarbons containing at least aboutthree (3) carbon atoms per molecule for each one hundred (100) moles offeedstock containing at least five (5) carbon atoms per molecule.

Hydrotreating is typically understood to involve the hydroprocessing ofpredominantly hydrocarbonaceous compounds containing at least fivecarbon atoms per molecule (“feedstock”) for the desulfurization and/ordenitrification of said feedstock, wherein the process is conducted: (a)at superatmospheric hydrogen partial pressure; (b) at temperaturestypically below 593.3° C. (1100° F.); (c) with an overall net chemicalconsumption of hydrogen; (d) in the presence of a solid supportedcatalyst containing at least one hydrogenation component; and (e)wherein: (i)the feedstock produces a yield of typically from about 100to about 130 moles (inclusive) of hydrocarbons containing at least threecarbon atoms per molecule for each 100 moles of the initial feedstock;or (ii) the feedstock comprises at least 50 liquid volume percent ofundeasphalted residue typically boiling above about 565.6° (1050° F.) asdetermined by ASTM D-1160 Distillation and where the primary function ofthe hydroprocessing is to desulftirize said feedstock or (iii) thefeedstock is the product of a synthetic oil producing operation.

Isomerization/dewaxing is typically understood to involvehydroprocessing predominantly hydrocarbonaceous oil having a ViscosityIndex (VI) and boiling range suitable for lubricating oil (“feedstock”)wherein said feedstock is contacted with solid catalyst that contains,as an active component, microporous crystalline molecular sieve, atconditions of elevated pressure and temperature and in the presence ofhydrogen, to make a product whose cold flow properties are substantiallyimproved relative to said feedstock and whose boiling range issubstantially within the boiling range of the feedstock.

More specifically, well known hydroprocessing catalyst componentstypically include at least one component of a metal selected from thegroup consisting of Group VIII metals, including Group VIII platinumgroup metals, in particular platinum and palladium, the Group VIII irongroup metals, in particular cobalt and nickel, the Group VI B metals, inparticular molybdenum and tungsten, and mixtures thereof. If thefeedstock has a sufficiently low sulfur content, e.g., less than about 1weight percent and preferably less than about 0.5 weight percent, theGroup VIII platinum group metals may be employed as the hydrogenationcomponent. In this embodiment. the Group VIII platinum group metal ispreferably present in an amount in the range of about 0.01 weightpercent to about 5 weight percent of the total catalyst, based onelemental platinum group metal. When the feedstock being treatedcontains more than about 1.0 weight percent sulfur, the hydrogenationcomponent is preferably a combination of at least one Group VIII irongroup metal and at least one Group VI B metal. The non-noble metalhydrogenation components are preferably present in the final catalystcomposition as oxides or sulfides, more preferably as sulfides.Preferred overall catalyst compositions contain at least about 2,preferably about 5 to about 40, wt. % Group VIB metal, more preferablymolybdenum and/or tungsten, and typically at least about 0.5, andpreferably about 1 to about 15, wt. % of Group VIII of the PeriodicTable of Elements, more preferably nickel and/or cobalt, determined asthe corresponding oxides. The sulfide form of these metals is morepreferred due to higher activity, selectivity and activity retention.

The catalyst components, e.g., hydroprocessing catalyst components, canbe incorporated into the overall catalyst composition by any one ofnumerous procedures as described.

Although the non-noble metal components can be combined into thecatalyst as the sulfides, this is not preferred. Such components areusually combined as a metal salt which can be thermally converted to thecorresponding oxide in an oxidizing atmosphere or reduced with hydrogenor other reducing agent. The composition can then be sulfided byreaction with a sulfur compound such as carbon disulfide, hydrogensulfide, hydrocarbon thiols, elemental sulfur, and the like.

Catalyst components can be incorporated into the composite alumina atany one of a number of stages in the catalyst preparation. For example,metal compounds, such as the sulfides, oxides or water-soluble saltssuch as ammonium heptamolybdate, ammonium tungstate, nickel nitrate,cobalt sulfate and the like, can be added by comulling, impregnation orprecipitation, after rehydration but before the composite is finallyagglomerated. In the alternative, these components can be added to thecomposite after agglomeration by impregnation with an aqueous, alcoholicor hydrocarbon solution of soluble compounds or precursors.

A further embodiment of the present invention is directed to a processfor the hydrotreating of a hydrocarbon feedstock in at least oneebullated bed reaction zone. More particularly, the hydrocarbonfeedstock is contacted with hydrogen in one or a series of ebullated bedreaction zones in the presence of a hydroprocessing catalyst comprisinga hydrogenation component of catalytic metals and derivatives asdescribed above deposited on agglomerates of the alumina compositedescribed herein.

As is well known these feedstocks contain nickel, vanadium, andasphaltenes, e.g., about 40 ppm up to more than 1,000 ppm for thecombined total amount of nickel and vanadium and up to about 25 wt. %asphaltenes. Further, the economics of these processes desirably producelighter products as well as a demetallized residual by-product. Thisprocess is particularly useful in treating feedstocks with a substantialamount of metals containing 150 ppm or more of nickel and vanadium andhaving a sulfur content in the range of about 1 wt. % to about 10 wt. %.Typical feedstocks that can be treated satisfactorily by the process ofthe present invention contain a substantial amount (e.g., about 90%) ofcomponents that boil appreciably above 537.8° C. (1,000° F.). Examplesof typical feedstocks are crude oils, topped crude oils, petroleumhydrocarbon residua, both atmospheric and vacuum residua, oils obtainedfrom tar sands and residua derived from tar sand oil, and hydrocarbonstreams derived from coal. Such hydrocarbon streams containorganometallic contaminants which create deleterious effects in variousrefining processes that employ catalysts in the conversion of theparticular hydrocarbon stream being treated. The metallic contaminantsthat are found in such feedstocks include, but are not limited to, iron,vanadium, and nickel.

While metallic contaminants, such as vanadium, nickel, and iron, areoften present in various hydrocarbon streams, other metals are alsopresent in a particular hydrocarbon stream. Such metals exist as theoxides or sulfides of the particular metal, or as a soluble salt of theparticular metal, or as high molecular weight organometallic compounds,including metal naphthenates and metal porphyrins, and derivativesthereof.

Another characteristic phenomenon of hydrotreating heavy hydrocarbons isthe precipitation of insoluble carbonaceous substances from theasphaltenic fraction of the feedstock which cause operability problems.The amount of such insolubles formed increases with the amount ofmaterial boiling, over 537.8° C. (1,000° F.) which is converted or withan increase in the reaction temperature employed. These insolublesubstances, also known as Shell hot filtration solids, create theoperability difficulties for the hydroconversion unit and therebycircumscribe the temperatures and feeds the unit can handle. In otherwords, the amount of solids formed limit the conversion of a givenfeedstock. Operability difficulties as described above may begin tomanifest themselves at solids levels as low as 0.1 wt. %. Levels below0.5 wt. % are generally recommended to prevent fouling of processequipment. A description of the Shell hot filtration test is found at A.J. J., Journal of the Inst. of Petroleum (1951) 37, pp. 596-604 by VanKerkvoort. W. J. and Nieuwstad, A. J. J. which is incorporated herein byreference.

It has been speculated that such insoluble carbonaceous substances areformed when the heavy hydrocarbons are converted in the hydroconversionunit, thereby rendering them a poorer solvent for the unconvertedasphaltenic fraction and hence creating the insoluble carbonaceoussubstances. The formation of such insolubles can be decreased by havingsome of the surface area in the hydroconversion catalyst be accessibleby very large pores so that most of the catalyst surface is accessibleto large asphaltenic molecules. Also, the large pores facilitatedeposition of nickel and vanadium in the hydrotreating catalyst withoutplugging the pores.

It has been discovered that the use of the porous composites as supportsin making catalysts, particularly hydroprocessing catalysts, provides ahigher initial activity than the catalysts supported on conventionalalumina.

While the benefit of higher initial activity is less significant in afixed bed operation, it is particularly important in an ebullated bedsystem. More specifically, in an ebullated bed system, increases ininitial activity are meaningful since there is an intermittent orcontinuous addition of catalyst to increase and maintain overall systemactivity. Since the overall activity of an ebullated bed system is theweighted average activity of all catalyst present varying from fresh todeactivated, the overall activity is increased by constant orintermittent addition of catalyst possessing a relatively higher initialactivity.

Hydrotreating operations are typically carried out in one or a series ofebullated bed reactors. As previously elucidated, an ebullated bed isone in which the solid catalyst particles are kept in random motion bythe upward flow of liquid and gas. An ebullated bed typically has agross volume of at least 10 percent greater and up to 70% greater thanthe solids thereof in a settled state. The required ebullition of thecatalyst particles is maintained by introducing the liquid feed,inclusive of recycle if any, to the reaction zone at linear velocitiesranging from about 0.02 to about 0.4 feet per second and preferably,from about 0.05 to about 0.20 feet per second.

The operating conditions for the hydrotreating of heavy hydrocarbonstreams, such as petroleum hydrocarbon residua and the like, are wellknown in the art and comprise a pressure within the range of about 1.000psia (68 atmos) to about 3,000 psia (204 atmos), an average catalyst bedtemperature within the range of about 700° F. (371° C.) to about 850° F.(454° C.), a liquid hourly space velocity (LHSV) within the range ofabout 0.1 volume of hydrocarbon per hour per volume of catalyst to about5 volumes of hydrocarbon per hour per volume of catalyst, and a hydrogenrecycle rate or hydrogen addition rate within the range of about 2,000standard cubic feet per barrel (SCFB) (356 m³/m³) to about 15.000 SCFB(2.671 m³/m³). Preferably, the operating conditions comprise a totalpressure within the range of about 1,200 psia to about 2,000 psia(81-136 atmos); an average catalyst bed temperature within the range ofabout 730° F. (387° C.) to about 820° F. (437° C.); and a LHSV withinthe range of about 0.1 to about 4.0; and a hydrogen recycle rate orhydrogen addition rate within the range of about 5.000 SCFB (890 m³/m³)to about 10,000 SCFB (1.781 m³/m³). Generally, the process temperaturesand space velocities are selected so that at least 30 vol. % of the feedfraction boiling above 1.000° F. is converted to a product boiling below1,000° F. and more preferably so that at least 70 vol. % of the subjectfraction is converted to a product boiling below 1,000° F.

For the treatment of hydrocarbon distillates, the operating conditionswould typically comprise a hydrogen partial pressure within the range ofabout 200 psia (13 atmos) to about 3,000 psia (204 atmos): an averagecatalyst bed temperature within the range of about 600° F. (315° C.) toabout 800° F. (426° C.); a LHSV within the range of about 0.4 volume ofhydrocarbon per hour per volume of catalyst to about 6 volumes ofhydrocarbon recycle rate or hydrogen addition rate within the range ofabout 1,000 SCFB (178 m³/m³) to about 10,000 SCFB (1,381 m³/m³).Preferred operating conditions for the hydrotreating of hydrocarbondistillates comprise a hydrogen partial pressure within the range ofabout 200 psia (13 atmos) to about 1,200 psia (81 atmos); an averagecatalyst bed temperature within the range of about 600° F. (315° C.) toabout 750° F. (398° C.); a LHSV within the range of about 0.5 volume ofhydrocarbon per hour per volume of catalyst to about 4 volumes ofhydrocarbon per hour per volume of catalyst; and a hydrogen recycle rateor hydrogen addition rate within the range of about 1,000 SCFB (178m³/m³) to about 6,000 SCFB (1,068 m³/m³).

The most desirable conditions for conversion of a specific feed to apredetermined product, however, can be best obtained by converting thefeed at several different temperatures, pressures, space velocities andhydrogen addition rates, correlating the effect of each of thesevariables and selecting the best compromise of overall conversion andselectivity.

All references herein to elements or metals belong to a certain Grouprefer to the Periodic Table of the Elements and Hawley's CondensedChemical Dictionary, 12^(th) Edition. Also, any references to the Groupor Groups shall be to the Group or Groups as reflected in this PeriodicTable of Elements using the CAS system for numbering groups.

All references in the claims to morphological properties defined interms of a weight, such as surface area, and pore volume are to beinterpreted as being on a metals free basis as defined in Equation 6,e.g., normalized to correct for any influence of the metal catalyticoxide (if present) on the weight of the material being analyzed. Unlessotherwise specified, all composites in powder form (non-agglomerated) inthe examples are filtered after rehydration and then exchanged to lowsoda by A/S exchange as described hereinabove prior to calcination. Noneof the extruded samples were A/S exchanged.

The following examples are given as specific illustrations of theclaimed invention. It should be understood, however, that the inventionis not limited to the specific details set forth in the examples. Allparts and percentages in the examples, as well as in the remainder ofthe specification, are by weight unless otherwise specified. Unlessotherwise specified herein, all surface area and pore propertydeterminations or recitations in the specification and claims are to beconstrued as being made on samples which have been oven dried at 138° C.(280° F.) and then calcined at 537.8° C. (1000° F.) for 2 hours atatmospheric pressure in air.

Further, any range of numbers recited in the specification or claims,such as that representing a particular set of properties, conditions,physical states or percentages, is intended to literally incorporateexpressly herein any number falling within such range, including anysubset of numbers within any range so recited.

EXAMPLE 1

To 1843 gm H₂O was added 14.4 gm, dry basis, of Laponite® RD, asynthetic hectorite clay available from LaPorte Industries, Ltd. Theresulting mixture was rapidly agitated for 20 minutes to disperse theclay. A very slightly cloudy solution forms, almost water clearindicating very well dispersed finely divided clay. To the Laponite®dispersion was added 23.5 gm of a 10% sodium gluconate aqueous solutionfollowed by 465.6 gm of a calcined active alumina. CP-3 from ALCOA. Theslurry was boiled under reflux for 24 hours. The slurry was filtered anddried overnight at 137.8° C. (280° F.). The resulting compositeparticles were then dry calcined for 2 hours at 537.8° C. (referred toherein as fresh), or calcined for 4 hours at 800° C. in an atmosphere of20 V % steam (referred to herein as steamed) and the surface areameasured for the fresh and steamed samples.

The percent conversion of the alumina sample to crystalline boehmite wasdetermined as follows:

(1) 100% boehmite is defined as an integrated intensity (area under thepeak) of the (020) peak of Catapal alumina.

(2) The (101) peak intensity of a Quartz plate is used as an X-rayintensity monitor.

(3) Data collection is performed on a Philips® 3720 automaticdiffractormeter equipped with a graphite diffract beam monochromator andsealed Cu X-Ray tube. The X-ray generator is operated at 45 kV and 40 mA

(4) Full width at half maximum (FWHM) and integrated intensity (areaunder the peak) of the (020) boehmite peak are obtained by curvefitting. In the case where one peak can not yield a good fit of thepeak, two peaks are used. In the case where two peaks are used for curvefitting, two crystallite sizes are obtained by using Equation 5. Percentboehmite of the two crystallite sizes are obtained by using Equation 4.

(5) The percentage of boehmite of a sample is determined by thefollowing equation:

%_(boehmite)=(I _(sample) *I _(quartz.c))/(I _(catapal) *I_(quartz.s))  (Equation 4)

wherein

I_(sample)=Integrated intensity of the (020) peak of sample;

I_(quartz.c)=Intensity of the (101) quartz peak, measured at the timeCatapal alumina was measured;

I_(catapal)=Integrated intensity of the (020) peak of the Catapalalumina; and

I_(quartz.s)=Intensity of the (101) quartz peak, measured at the timesample was measured.

Boehmite crystallite size (L) is determined bv the following procedure.The sample is hand ground with a mortar and pestle. An even layer of thesample is placed on 3.5 gms polyvinyl alcohol (PVA) and pressed for 10seconds at 3,000 psi to obtain a pellet. The pellet is then scanned withCu K Alpha radiation and the diffraction pattern between 22 and 33degrees (2θ) is plotted. The peak at 28 degrees (2θ) is used tocalculate the crystallite size using Equation 5 and the measured peakwidth at half height.

L(size in Å)=82.98/FWHM(2θ°) cos (θ)(Equation 5)

wherein

FWHM=Full width at half maximum; and

θ=The angle of diffraction between X-ray beam and planar surface onwhich the sample is sitting.

The resultant properties analyzed are reported at Table 2 and FIG. 1 anddesignated Run 2. The addition of 3% Laponite® gave increased fresh andsteamed surface areas compared to Comparative Example 1. FIG. 1 alsoillustrates a large increase in total nitrogen pore volume and shift tolarger pores.

COMPARATIVE EXAMPLE 1

Example 1 was repeated except that no Laponite® was added to the sample.The results are reported at Table 2, FIG. 1 and designated Run 1.

TABLE 2 EFFECT OF ADDITION OF 3% LAPONITE ® ON THE SURFACE PROPERTIES OFBOEHMITE OBTAINED BY REHYDRATION OF ACTIVE ALUMINA RUN NO. 1 2 Comp Ex.1 Example 1 Wt. % Laponite ® 0 3 Boehmite Properties-After Hot Age 24Hours At 100° C. (212° F.) Average Pore Diameter (Å) 149 197 Total PoreVolume (cc/g) 0.668 1.378 Pore Volume > 600Å (cc/g) 0.046 0.298 MesoporePore Volume (cc/g) 0.205 0.774 Mesopore Content (% TPV) 30.6 56 2Macropore SA (m²/g) 2.8 17.2 Mesopore Pore Mode (Å) 70 200 % increase inMesopore Pore Mode N/A 185 SURFACE AREA 2 Hours @ 537.8° C. (Fresh)(m²/g) 179 279 Micropore Surface Area (Fresh) (m²/g) 0 0 MesoporeSurface Area (Fresh) (m²/g) 179 279 % Conversion Of Active Alumina 83 78To Boehmite SA - 4 Hours @ 800° C., 20V % Steam (m²/g) 112 182

EXAMPLE 2

Example 1 was repeated except that the level of the synthetic hectorite,Laponite®, was varied from 0.1 to 10 wt. % of the total solids(Laponite®+alumina) (corresponding to Runs 3-12). After a 24 hour age atreflux, the samples were filtered and dried overnight at 137.8° C. (280°F.). The boehmite crystallite size of selected samples was measured aswell as the surface area after two hours at 537.8° C. (1000° F.), or 4hours in 20 V % steam at 800° C. Also measured was the dispersabilityindex (DPI) of the composite particles. This test measured the % ofparticles having a particle diameter of <1 micron after dispersing inwater with a measured amount of HCl (237 milliequivalents/mole alumina)and mixing. The results of the level of synthetic hectorite on theboehmite properties are summarized at Table 3. It will be observed thatthe dispersible swelling clay:

(a) increased total nitrogen pore volume and average pore diameter to amaximum value in the 3-5 wt. % range;

(b) reduced Boehrnite crystallite size;

(c) significantly increased fresh and steamed surface area and nitrogenpore volume; and

(d) increased dispersability of the alumina when 3 wt. % or more claywas added.

It was also noted that as the wt. % synthetic clay added was increased,the hardness of the oven dried boehmite increased. At 0 wt. % the ovendried material was a soft powder, at 3 wt. % clay it was moderatelyhard, while at 5-10 wt. % it was quite hard. This is believed toindicate that extrudates/beads made from the composite particles havinglevels of 3 wt. % and above would have a high crush strength. Plots ofthe nitrogen pore size distribution at clay levels from 0 to 1 wt. % areshown at FIG. 2, and those for clay levels between 0 and 6 wt. % areshown at FIG. 3.

FIG. 2 actually shows a decrease in the mesopore pore mode at low levelsof Laponite®. FIG. 3 shows a consistent shift to higher mesopore poremodes at increasingly higher clay concentrations between 2 and 5 wt. %.Table 3 shows a peaking of total pore volume (TPV), average porediameter (APD), and fresh and steamed surface area (SA) peaks at a clayconcentration of 5 wt. %.

TABLE 3 EFFECT OF THE LAPONITE ® LEVEL ON THE FRESH AND STEAMEDPROPERTIES OF BOEHMITE Run No. 3 4 5 6 7 8 9 10 11 12 WT. % Laponite ® 00.5 1 2 3 4 5 6 8 10 % Conversion Active Alumina 83 NA 72 72 78 79 65 NA68 NA To Boehmite *Crystallite Size (Å) 128 114 99 81 94 79 62 63 74 69DPI (%) 21 20 27 99 100 100 100 100 100 2 hours @ 537.8° C. BET SA(m²/g) 179 263 289 317 279 311 315 290 295 286 Micro SA (m²/g) 0 0 0 0 00 0 0 0 0 Meso SA (m²/g) 179 263 289 317 279 311 315 290 295 286 AveP.D. (Å) 149 90 95 122 197 153 188 112 89 88 Total P.V. (cc/g) 0.6680.592 0.687 0.966 1.378 1.184 1.479 0.813 0.659 0.629 **SA On Dist(m²/g) 276 456 450 436 341 373 388 354 340 335 PV>600Å (cc/g) 0.0460.054 0.055 0.226 0.298 0.222 0.176 0.061 0.035 0.034 Mesopore Content(%) 34 16 22 31 55 68 67 47 42 37 Macropore Content (%) 8.6 10 9 21 2626 15 8 6 6 Mesopore Pore Mode (Å) 70 39 39 140 206 200 180 103 120 125% Increase In Pore Mode N/A −45 −45 100 194 186 154 47 71 70 4 hours @800° C. (20% STEAM) BET SA (m²/g) 112 131 150 184 182 198 228 209 213203 Micro SA (m²/g) 0 Meso SA (m²/g) 112 Ave. P.D. (Å) 230 Total P.V.(cc/g) 0.643 SA On Dist. (m²/g) 142.5 PV>600Å (cc/g) 0.07 ***% SA Ret.62.6 49.8 51.9 58 65.2 63.7 72.4 72.1 72.2 71 Note: Total N₂ Pore VolumeMeasured at a Relative Pressure of 0.995 P/Po. * = After Aging Slurry at100° C. for 24 Hours ** = Surface Area Calculated from N₂ Pore SizeDistribution for Pores Having Pore Diameter 20-600Å *** = % Surface AreaRetained After Steaming

EXAMPLE 3

This example illustrates the effect of drying conditions and totalvolatiles (TV) measured at 954.4° C. (1750° F.) on the dispersability ofthe synthetic hectorite and accordingly the alumina product.

A two gallon autoclave batch of synthetic hectorite was prepared inaccordance with Example 2 of U.S. Pat. 4.049,780.

After autoclaving, the gel slurry of synthetic hectorite was filtered,washed with water and divided into Samples 1 to 4 as follows:

(1) held as filter cake, TV=83.43%

(2) oven dried overnight at 100° C. (212° F.), TV=12.83%

(3) spray dried (S.D.) at 130° C. outlet, TV=19.38%

(4) spray dried at 180° C. outlet, TV=15.45%

Spray dried Samples 3 and 4 were prepared by reslurrying the filter caketo about 2% solids before spray drying in a small bench top spray dryer.

Four separate alumina/synthetic hectorite composites were prepared inaccordance with Example 2 but using 3 wt. % of one of the synthetichectorite Samples 1 to 4. The solids content of each clay/alumina slurrywas 17 wt. %. More specifically, each of the above synthetic hectoriteSamples 1 to 4 were slurried in water with rapid agitation for ½ hour.Calcined alumina was then added to each slurry and boiled for 24 hoursunder reflux with good agitation. The effect on the alumina pore volumeof the synthetic hectorite is shown at Table 4, Runs 13 to 16, The TotalPore Volume of the boehmite product increases as the dispersability ofthe synthetic hectorite increases. It was visually noted that the waterdispersed synthetic hectorites increased in clarity (and hencedispersity) in the order: filter cake <oven dried <S.D. @ 130° C. <S.D.@ 180° C. which is the order of increasing pore volume, average porediameter and dispersability index of the alumina. Accordingly, the shiftin pore volume can be controlled by the level of dispersible swellingclay used and/or the degree of dispersion of the swelling clay. Thedegree of dispersion, or the size of the clay particles in thedispersion, can be controlled by the clay synthesis conditions (molarinput ratios, autoclave temperature, etc.) or drying conditions. Notefurther that the fresh and steamed S.A.'s of Sample 4 is still higherthan Sample 1 while achieving a much higher TPV.

TABLE 4 EFFECT OF SYNTHETIC HECTORITE DRYING CONDITIONS ON THE SURFACEPROPERTIES OF BOEHMITE FROM ACTIVE ALUMINA @ 3% CLAY RUN NO. 13 14 15 16Synthetic Hectorite 1 2 3 4 Sample # Type of Drying Not Oven Dried SprayDried Spray Dried Dried (Filter Overnight At At 130° C. At 180° C. Cake)212° F.) Clay TV 83.43% 12.83% 19.38% 15.45% Wt. % Clay Added 3% 3% 3%3% Alumina Properties [Calcined 2 hours @ 537.8° C. (1000° F.)] BETSurface Area 261 295 285 264 (m²/g) Ave. Pore Diameter 119 172 195 216(A) Total Pore Volume 0.773 1.268 1.387 1.428 (cc/g) DispersabilityIndex 20 36 62 94 (%) HydroThermal Stability 4 Hrs. @ 800° C. 195 238230 213 20V % Steam Surface Area (m²/g)

EXAMPLE 4

This example illustrates the impact of dispersability on themorphological properties of the composite as mediated by the clayforming reaction temperature.

A first synthetic hectorite sample labeled SH-1, designated Run 16-1,was prepared generally in accordance with Example 3 at inputs of 1.49moles SiO₂, 1.0 mole MgO, 0.06 mole Li, 0.08 mole Na by adding 97.9 gmsilicic acid (H₄SiO₄), 58.3 gm Mg(OH)₂, 2.55 gm LiCl, and 4.7 gm NaCl to1, 169 gm H₂O and boiled at reflux for 24 hours. A second synthetichectorite (SH-2), designated Run 16-2, was prepared using inputs of 87.4gm silicic acid, 58.3 gm Mg (OH)₂ and 10.5 gm LiCl added to 1,083 gm H₂Oand hot aging in a plastic bottle for about 24 hours at 101.7° C. (215°F.). Both samples had X-ray diffraction patterns of hectorite. A slurryof each clay was prepared by blending in water for 2 minutes, and tothis slurry was added 291 gm, dry basis, CP-3 calcined alumina and 1.5gm sodium gluconate. The synthetic clay/alumina weight ratio was 3/97.This slurry was boiled under reflux for 24 hours, filtered and ovendried. It was observed during reflux of the synthetic hectorite startingmaterials for both SH-1 and SH-2, that the particles were coarse and didnot disperse to a colloidal sol.

Nitrogen pore size distribution results, are summarized at FIG. 4 alongwith the plot from the control of Run 3. These results illustrate thatthis alumina prepared with non-dispersible or poorly dispersed synthetichectorites (SH-1 and SH-2) do not have the same shift in nitrogen poresize distribution of even the control without any synthetic hectorite.The amounts of reactants for SH-1 and SH-2 are summarized at Table 5.

TABLE 5 RUN NO. 16-1 16-2 Sample No. SH-1 Sample No. SH-2 Reactants(gms) (gms) H₄SiO₄ 97.9 87.4 Mg(OH)₂ 58.3 58.3 LiCl 2.55 10.5 NaCl 4.7 0H₂O 1.169 1.083

In general, the higher the synthetic hectorite reaction formingtemperature or the longer the time, the higher will be itsdispersability. Thus, reaction forming temperatures of at least 150 to200° C. are preferred. Such temperatures are achievable with anautoclave.

EXAMPLE 5

This example illustrates the effect of employing highly purifiednon-fluorinated hectorite in place of a synthetic hectorite. Two samplesof highly purified natural hectorite were obtained from the AmericanColloid Co. These clays, Hectalite 200 (designated separately NH-1) andHectabrite DP (Designated NH-2), were dispersed for 1 minute in ablender. Calcined alumina and sodium gluconate were then added to eachdispersion to give 3% clay and 97% calcined alumina (CP-3, ALCOA). Thegluconate level was 0.5 wt. % on an alumina basis. Both slurries wereboiled under reflux for 24 hours with agitation, filtered, and ovendried. Nitrogen pore size distribution results are reported at FIG. 5.This procedure was repeated using clay samples SH-1 and SH-2 anddesignated Runs 20 and 21.

A reference alumina sample designated CE-2 was also prepared inaccordance with Example 5, except the clay was omitted.

A comparison of the plots of FIGS. 1 and 3 with those of FIG. 5illustrate only a slight shift of the mesopore mode to higher diameterswhen using natural hectorite versus synthetic hectorite (Runs 20-21).Other morphological properties of the natural hectorite samples (Runs18-19), the sample from Run 7, and Comparative Sample CE-2 (Run 17) arealso reported at Table 6.

TABLE 6 EFFECT OF VARIOUS HECTORITES ON BOEHMITE PORE STRUCTURE RUN NO.17 18 19 20 21 7 SAMPLE# CE-2 NH-1 NH-2 SH-1 SH-2 Table 3 Run 7 CLAY 0HECTALITE HECTABRITE SYN HECT SYN HECT LAPONITE ® WT % Added 0 4 4 3 3 3BET SA (m²/g) 179 235 221 257 263 279 Mic SA (m²/g) 0 0 0 0 0 0 Meso SA(m²/g) 179 235 221 257 263 279 Ave. P.D. (Å) 149 166 127 106 102 197Total PV (cc/g) 0.668 0.979 0.702 0.681 0674 1.378 SA On Dist. (m²/g)275.9 319.6 276.8 429.9 441.2 341 PV>600Å (cc/g) 0.046 0.143 0.039 00610.049 0.298

EXAMPLE 6

This example illustrates the effect of a synthetic hectorite onhydrothermal stability of a different calcined alumina. Thus, a calcinedalumina available from Porocel under the tradename AP-15 was used tomake composites of Boehmite/Laponite® using the procedure of Example 1,except the levels of dispersible hectorite (Laponite® RD) were varied at0, 1.5, and 3 wt. % and no sodium gluconate was employed (Run 22). Theresults indicate good hydrothermal stability was obtained, with orwithout added gluconate. The stability is very comparable to thatobtained with the CP-3 alumina.

The resulting samples were aged in steam (20%) for 4 hours at 800° C.and the BET surface area in m²/g determined. In addition, compositesamples were prepared in accordance with Example 1 using CP-3 aluminaexcept that the Laponite® content was varied at 0. 0.1, 0.2, 0.25, 1.5,2, 3 and 5 wt. % and the resulting products aged as described above forthe AP-15 derived samples. The results are shown at FIG. 6 as Run 23.

EXAMPLE 7

This example illustrates the effect of varying the point of addition ofsynthetic Laponite® before and after rehydration of the calcinedalumina.

A batch of boehmite from calcined alumina was prepared as follows: to1888 gms H₂O in a 3L glass container was added 24.4 gms of a 10 wt. %sodium gluconate solution and then 480 gms, dry basis, of calcined CP-3alumina from ALCOA. This slurry was boiled for 24 hours under reflux torehydrate the alumina. The rehydrated alumina was then divided into 5equal portions. To each was added varying amounts of Laponite® RD(Laporte) at 0, 2, 4, 6 and 8 wt. %. The surface area of these materialswas determined after aging 4 hours in 20% steam at 800° C. and theresults reported at FIG. 7 as Run 24. The above procedures were repeatedexcept that the Laponite® was added at 0, 0.25, 1.0, 2.0, 2.25, 3.0,3.75, 4.0, 5.0, 6.0, 8.0, and 10 wt. % amounts prior to refluxing thealumina, i.e., prior to rehydration. The resulting products were thenalso aged in steam (20%) for 4 hours at 800° C., the BET surface areadetermined and results summarized at FIG. 7. Run 25. As can be seentherefrom addition of the dispersible hectorite before rehydration (Run25) gives a more hydrothermally stable product versus addition afterrehydration (Run 24). It is thought that this is due to the higher freshsurface area, pore volume and average pore diameter of this product, aswell as the better dispersion of the clay within the alumina, when it isadded at the start of the rehydration.

EXAMPLE 8

This example illustrates the effect on hydrothermal stability ofpre-milling the slurry containing the dispersible synthetic hectoriteand a calcined alumina (CP-3, ALCOA).

To 8,331 gm H₂O was added with rapid agitation 51.9 gm Laponite® RD(Laporte, TV=13.26%). The slurry was aged at room temperature withagitation for 20 minutes to disperse the clay. A substantially clearsolution formed indicating a good, colloidal dispersion of the clay. Tothis was added 1,616.7 gm CP-3 (TV=10%) with good agitation. The slurrycontaining 3 wt. % Laponite® was then milled under severe (80% media,0.75 l/1 min.) conditions in a 4L DRAIS mill. The milled slurry wasboiled under reflux for 24 hours and a portion filtered and oven dried.The resulting sample is designated Run 28. The designation 0.75 L/1 minrefers to an input/output of 0.75 liters per minute to and from themill.

The above procedure was repeated except the premilling was omitted. Thissample is designated Run 27.

In addition, a control was prepared wherein the Laponite® was omittedand no premilling was employed. This sample was designated Run 26.

All three samples were then divided into two parts and the first partaged at 4 hours in 20% steam at 800° C. and the second part aged at537.8° C. for 2 hours. The surface area was then determined for eachaged sample. The hydrothermal stability results are summarized at Table7 and the nitrogen pore properties depicted at FIG. 8.

Table 7 indicates that premilling leads to a product with much higherfresh surface area and steamed surface area than the no clay base caseor the unmilled sample with the same level of dispersible clay. Nitrogenpore size distribution results indicate premilling gives a small shiftto more pores of smaller diameter but higher TPV.

TABLE 7 3% Laponite ® 3% Laponite ® with Milling 0% Laponite ® w.o.Milling Before Aging RUN NO. 26 27 28 SA (m²/g) SA (m²/g) SA (m²/g) 4hrs @ 800° C. SA 115-119 195-210 281 2 hrs @ 537.8° C. 199 279 345 AveP.D. (Å) 153 197 169 Total Pore Vol. (cc/g) 0.761 1.378 1.461 MesoporePore Mode 69 111 108 (Å) % Increase in Mesopore pore Mode N/A 61 56

EXAMPLE 9

This example illustrates the effect and degree of pre-dispersionachieved with a laboratory preparation of synthetic hectorite dried to alow TV (9.64%).

The synthetic hectorite was prepared by slowly adding a solution of 75.3gm Na₂CO₃ dissolved in 289 gm H₂O to a solution of 183.5 gm MgSO₄•7H₂O+3.4 gm LiCl. Then a solution of 267.4 gm silicate (27.11% SiO₂)diluted with 826 gm H₂O was added over a half hour period. The resultinggel slurry was boiled for 30 minutes to remove carbonate then autoclavedfor 2 hours at 200° C. filtered, washed on the filter with 1 L 65.6° C.(150° F.) deionized water and dried at 135° C.

Portions were reslurried in water as follows:

Run 29 stir with moderate agitation for 30 minutes Run 30 disperse withSilverson mixer for 10 minutes at 10,000 RPM Run 31 stir for about 18hours with magnetic stirring bar.

To each of the above slurries was added enough calcined alumina (CP-3,ALCOA) to make a 15% solids slurry with 3 wt. % of the synthetichectorite and 97% alumina. The slurry was boiled for 24 hours underreflux with agitation. The slurry was filtered and over dried at 137.8°C. (280° F.). The average pore diameter of each product derived fromRuns 29 to 31 was measured after 2 hours at 537.8° C. (1000° F.)calcination. The surface area and TPV were determined and the resultssummarized at Table 8.

The average pore diameter increased from 147 to 159 to 176 Å for Runs 29to 31 respectively, indicating better dispersion is achieved asdispersing time and/or severity was increased. It is believed that thissample was difficult to disperse due to its relatively low totalvolatiles of 9.64%. Thus, dispersability of the clay can be enhanced bycontrolling the TV, the degree of clay dispersion, or the claycrystallite size, which in turn control the average pore diameter of thealumina.

TABLE 8 THE EFFECT OF THE DEGREE OF DISPERSION OF THE SYNTHETICHECTORITE ON THE TOTAL N₂ PORE VOLUME AND AVERAGE PORE DIAMETER OF THEBOEHMITE PRE- PARED BY REHYDRATION OF ACTIVE ALUMINA RUN NO. 29 30 31WT. % Synthetic Hectorite 3 3 3 Clay Dispersion 30 Min. 10 Min. 18 Hrs.Mild Agit. Silverson Mild Agit. (10,000 rpm) 2 hrs @ 537.8° C. (1000°F.) Alumina Properties Surface Area (m²/g) 286 284 284 Pore Diameter (Å)147 159 176 N₂ Pore Vol. (cc/g) 1.05 1.13 1.23

Total volatiles of the synthetic hectorite, sample employed for Runs29-31 was only 9.64%, and is believed to have made this clay difficultto fully disperse regardless of the degree of agitation.

COMPARATIVE EXAMPLE 2

This example illustrates the effect of non-swellable clays such asKaolin, or calcined Kaolin on pore structure.

Example 1 was repeated except that the clay employed was kaolin orcalcined kaolin at the amounts reported in Table 9. The resultingcomposites are designated as Run 33 (kaolin), Run 34 (calcined kaolin at6 wt. %), and Run 35 (calcined kaolin at 12 wt. %). The calcination ofthe kaolin was conducted at 900° C. for 0.66 hours. The surfaceproperties of these materials were measured as was the fresh surfacearea and the results reported at Table 9. A control alumina with no claywas also employed prepared by the same method and designated Run 32. Theamounts of kaolin present in the composite particles is also reported atTable 9. Nitrogen desorption data for Runs 32 to 35 is also reported atFIG. 9. As can be seen from Table 9 and FIG. 9, the kaolin actuallycaused a reduction in average pore diameter (APD) and Total Pore Volumerelative to the control but an increase in surface area. Kaolin is anon-swellable clay.

EXAMPLE 10

This example illustrates the effect on pore properties of using the lesspreferred montmorillonite clay.

Comparative Example 2 was repeated except that montmorillonite clay,available from Southern Clay Products under the tradename Gelwhite L.replaced the kaolin clay at 6 wt. % (Run 36) and 12 wt. % (Run 37). Thecontrol at 0 wt. % clay is designated Run 32. The results are summarizedat Table 9 and FIG. 10. As can be seen therefrom, the alumina poreproperties and surface area are higher at 6 wt. % than 12 wt. % clay.Moreover, the mesopore pore mode does not appear to shift to the right,and the pore size distribution spreads out. This is believed to beattributable to the fact that montmorillonite is difficult to dispersewell without some other treatment such as significant milling to reducethe particle size, ion-exchange, or the use of dispersants such as tetrasodium pyrophosphate.

EXAMPLE 11

Comparative Example 2 was repeated except that sodium silicate replacedthe kaolin clay at 0.5 wt. % (Run 39) and 1 wt. % (Run 38). The controlwithout silicate is Run 32.

TABLE 9 EFFECT OF VARIOIUS ADDITIVES ON THE BOEHMITE PORE STRUCTURE RUNNO. 32 33 34 35 36 37 38 Clay None Kaolin Calcined Calcined Montmo-Montmo- % SiO₂ from Kaolin Kaolin rillonite rillonite Silicate Wt. % 012 6 12 6 12 1 2 hrs. @ 537.8° C. (1000° F.) Properties BET Surface Area(m²/g) 199 186 298 311 246 239 281 Ave. Pore Diameter (Å) 153 129 91 77138 116 102 Total N₂ Pore Volume (cc/g) 0.761 0.598 0.675 0.603 0.8480.692 0.718 Mesopore Pore Mode (Å) 69 58 39 39 70 70 40 % Increase inMesopore Pore N/A −16 −44 −44 1 1 −42 Mode

The pore properties and surface area were tested and the resultssummarized at Table 9 (for Run 38) and FIG. 11. As can be seen therefromthe silicate actually induced a sharp shift of the mesopore pore mode tosmaller pore diameters. Thus, the silicate derived composites can beblended with the hectorite derived composites to shift the porestructure as desired for each intended application.

EXAMPLE 12

This example illustrates the effect on hydrothermal stability of millingthe calcined alumina prior to rehydration in the presence of swellableclay.

Thus, Example 8, Run 28 was repeated and the combined slurry ofLaponite® (at 3 wt. %) and calcined alumina was milled prior torehydration and designated Run 42. After reflux for 24 hours at 100° C.(212° F.) the boehmite was filtered and oven dried at 140° C. for 6hours. Portions were calcined at 800° C. in an approximate 20% steamatmosphere for varying times and then the surface areas measured. Theabove procedure was repeated except that the milling step was omittedand the product designated Run 41. A control containing no Laponite® andno milling step was also made and designated Run 40 and subjected to thesame steam treatment and surface area determinations. The results aresummarized at FIG. 12. FIG. 13 expresses the data points of each Run ofFIG. 12 as a percent of the surface area obtained on a fresh sample,heated for 2 hours at 537.8° C. (1000° F.) (i.e., 0 hours heated insteam). This percentage is referred to as a % surface area retention. Ascan be seen therefrom, the surface area stability increases in the order0% Laponite® (Run 40) <3% Laponite® (Run 41) <3% Laponite® and milling(Run 42).

EXAMPLE 13

This example illustrates the effect of post-synthesis addition of Nasilicate to boehmite derived from rehydrated calcined alumina.

A sample of calcined alumina available from ALCOA under the tradenameCP-3 (Run 43) and a sample of calcined alumina available from Porcelunder the tradename AP-15 (Run 44) were each separately slurried inwater, containing 0.5 wt. % (alumina basis) sodium gluconate, at asolids content of 17 wt. % and hot aged for 24 hours under reflux. Bothbatches were then divided up and varying amounts of sodium silicateadded, aged for about 30 minutes at 21° C. the pH adjusted to 9.0 with4% H₂SO₄, filtered, reslurried with ammonium sulfate to remove Na₂O,filtered, water washed and dried. Each sample was steamed for 4 hours at800° C. in an atmosphere of about 20 V % steam and the surface areameasured.

The results on the products of each run are summarized at FIG. 14. Ascan be seen therefrom the silicate significantly enhances thehydrothermal stability of the boehmite samples.

EXAMPLE 14

This example illustrates the effect of adding silicate to the compositeof the present invention after formation thereof.

Two batches of boehmite were prepared using 3 wt. % (Run 45) and 5 wt. %(Run 46) Laponite® RD (Laporte) as the source of dispersible clay.Slurries of the Laponite® were prepared by adding the clay to water withrapid agitation and mixing for 20 minutes. Sodium gluconate was added at0.5 wt. % (alumina basis) followed by addition of CP-3, a calcinedalumina from ALCOA. Each slurry was boiled under reflux for 24 hourswith agitation, filtered and oven dried overnight at 137.8° C. (280°F.). Portions of each product were reslurried in water, sodium silicateadded and the mixture aged 30 minutes at 21° C. The pH was adjusted to9.0 with 4% H₂SO₄, filtered, exchanged as a slurry with ammonium sulfateto remove Na₂O, filtered water washed and oven dried at 137.8° C. (280°F.). Each sample was then subjected to contact with 20 wt. % steamatmosphere for 4 hours at 800° C., and the surface area determined. Aplot of wt. % SiO₂ versus steamed surface area is provided at FIG. 15.As can be seen therefrom, very high surface areas were obtained.Moreover, a comparison of these steamed surface areas with the clay freesamples from Example 13 (FIG. 14), is provided at FIG. 16. As can beseen therefrom, improved surface areas were obtained by combining theaddition of the dispersible clay with post-synthesis addition ofsilicate. It is believed that part of the reasons for the higher steamedsurface area of the aluminas with dispersible clay is the higher freshsurface area, higher pore volume and higher average pore diameter.

EXAMPLE 15

This example illustrates the effect of post-synthesis silicate additionto an alumina prepared with a poorly dispersed synthetic hectoriteprepared at only 100° C. (212° F.) (the lower prep temperature inducinga much lower degree of dispersability).

A batch of synthetic hectorite was prepared by adding 97.9 gm silicicacid (H₄SiO₄) to 1169 gm H₂O in a 3L resin kettle under agitation. Tothe kettle was added under agitation, 58.3 gm Mg (OH), 2.55 gm LiCl, and4.7 gm NaCl. The slurry was refluxed for 24 hours, filtered, washedthree times with water at 65.6° C. (150° F.) and dried at 137.8° C.(280° F.). An X-ray diffraction pattern very similar to that ofLaponite® RD was obtained. Enough of this dried material was blended in800 ml H₂O for 2 minutes to give 3% of the final alumina weight, and todisperse it as much as possible. In contrast to Laponite® RD, an opaqueslurry was obtained, indicative of a low degree of dispersion. Thisslurry was added to a 3L resin kettle along with 0.5 wt. % sodiumgluconate (alumina basis), and additional H₂O to give a 17% solidsslurry. CP-3 (calcined alumina from ALCOA) was then added. This slurrywas boiled under reflux for 24 hours, filtered and dried at 137.8° C.(280° F.). Portions were reslurried in water, and varying amounts ofsilicate added as reported at FIG. 17, Run 49. Each sample was steamedfor 4 hours, 800° C., in approximately 20% steam and the surface areasdetermined.

The above procedure was repeated except that highly dispersed Laponite®RD replaced the synthetic hectorite made and used for Run 49. Eachsample of the resulting product was tested for surface area and theresults designated Run 48. These results are plotted in FIG. 17.

A control was also made following the procedures of Run 49, except noclay was employed. The surface areas were plotted in FIG. 17 anddesignated Run 47.

As can be seen from FIG. 17, the surface area stability increases in theorder of no clay+silica <poorly dispersed clay+silica <well dispersedclay+silica.

EXAMPLE 16

This example illustrates the effect of premilling the slurry containingcalcined alumina and dispersible clay before rehydration and with postsynthesis addition of sodium silicate.

A slurry was prepared by dispersing 51.9 gm Laponite® RD (TV=13.26%) in8.331 gm H₂O with rapid agitation for 20 minutes, followed by additionof 1,616.7 gm of CP-3 (a calcined alumina from ALCOA, TV=10%). Theresulting slurry was milled in a 4L DRAIS mill at a rate of about1L/minute with a glass media loading of about 60%. The slurry was hotaged for 24 hours at boiling under reflux, filtered and oven dried.Samples of this boehmite alumina were reslurried in water, with varyingamounts of sodium silicate as reported at Table 10, aged ¼ hour at 21°C., pH adjusted to 9.0 with 4% H₂SO₄, filtered and designated Run 52.The above procedure was repeated except that the milling step wasomitted and resulting samples designated Run 51. A control was alsoprepared except that the milling step and the silica and clay additionwas omitted. The control was designated Run 50. Each of the samples ofRuns 50 to 52 was reslurried in water containing ammonium sulfate for ¼hour, filtered, water washed and oven dried. This exchange was made toreduce Na₂O to a low (<0.25 wt. %) level. Samples were then calcined for4 hours at 800° C. in a 20 V % steam atmosphere. The effects of thesilicate level as well as milling/not-milling and the presence of thedispersible hectorite on the steamed surface area is summarized at Table10. Milling gives the highest surface area with or without addedsilicate.

TABLE 10 RUN NO. 50 51 52 ALUMINA ALUMINA ALUMINA FROM CP-3 FROM CP-3WITH MILLING (No-Clay) W.O MILLING BEFORE AGE (No-Milling) (3% Clay) (3%Clay) SA SA SA (m²/gm) (m²/gm) (m²/gm) 4 hrs @ 800° C. SA 115-119195-210 281 With 4% SiO₂ 179 250 302 With 8% SiO₂ 195 279 311 2 hrs @537.8° C. (1000° F.) BET SA 199 279 345 Ave. P.D. 153 197 169 Total PoreVolume 0.761 1.378 1.461 % SA Retention (On SiO₂ SA Basis) 0% SiO₂ 58.872.4 8 4% SiO₂ 89.9 89.6 87.5 8% SiO₂ 98 100 90.1

EXAMPLE 17

This example illustrates the effect of adding sodium silicate before orafter rehydration (hot aging) of the calcined alumina slurry.

Slurries were prepared of the calcined alumina (CP-3, ALCOA) withvarying silicate levels and then hot aged for 24 hours at boiling andunder reflux. The resulting samples are grouped as Run 54. Slurries werealso prepared using calcined alumina only (designated Run 53), orcalcined alumina to which 3% of a dispersible Hectorite (Laponite® RD)was added before the hot aging (designated Run 55). The latter twopreparations were treated with varying amounts of silicate after the hotage, which amounts are shown at FIG. 8. All samples were exchanged withammonium sulfate to reduce Na₂O to a low level (<0.25 wt. %) beforesteaming at 800° C. for 4 hours in an atmosphere of about 20% steam. Thesurface areas of the resulting products for Runs 53 to 55 are reportedat FIG. 18. The surface area results indicate the addition of silicateimproves the hydrothermal stability of all the samples. However, thesurface areas follow generally in the order Al₂O₃+3% Laponite®>silicateaddition after age >silicate addition before age. Addition of silicatebefore the hot age also reduces the pore volume/pore diameter of theBoehmite.

EXAMPLE 18

This example illustrates the effect of adding silicate after rehydrationon the steamed pore structure of a boehmite alumina/Laponite® composite.

Samples of a 3% Laponite® containing boehrnite with varying silicatelevels of 0 wt. % (Run 56), 2 wt. % (Run 57), 4 wt. % (Run 58) and 8 wt.% (Run 59), were prepared as described in Example 14. After 4 hours at800° C. treatment in 20% steam, the nitrogen pore size distributionswere measured. The results are reported at FIG. 19. FIG. 19 shows onlyminor changes in pore distribution between 0, 2, 4% added silicate,however, at 8% silicate, the pores do shift to a lower average porediameter.

EXAMPLE 19

This example illustrates the preparation of the alumina/swellable claycomposite which is used in the following example to make agglomeratestherefrom. 7,014 g OB (Original Basis not corrected for TV) (3% byweight, based on the combined weight of alumina and clay) of a synthetichectorite Laponite® was slurried in 350 gallons of city water at ambienttemperature. The slurry was mixed in an open tank with a 4 paddleagitator for 30 minutes at maximum agitation (about 300 rpm) to assure agood dispersion. Then, 234 kg (515 pounds) OB of Alcoa CP-3 activatedalumina were slowly added to the slurried Laponite®. After all the CP-3was added, the slurry was heated to 93.3° C. (200° F.) where it was heldfor 24 hours. The slurry was filtered and washed with 65.6-71.1° C.(150-160° F.) city water on a three-wash-zone Eimco belt filter. Thefilter cake was spray-dried at 371.1° C. (700° F.) inlet/121.1° C. (250°F.) outlet temperature.

The resulting product is designated Sample No. AX-1.

A summary of the properties of AX-1 is provided at Table 11 and a plotof its nitrogen pore size distribution is provided at FIG. 20. The dataon AX-1 in FIG. 20 is designated Run 60.

COMPARATIVE EXAMPLE 3

A control sample of boehmite alumina was synthesized as follows.

To 4,950 parts by volume of water heated in a reactor to 63.3° C. (146°F.) under constant agitation was added 150 parts by volume of a 7.0 wt.% solution of aluminum sulfate as Al₂O₃ and the resultant mixturestirred for four minutes. Two separate solutions were thensimultaneously fed to the reactor. The first solution was 7.0 wt. %aluminum sulfate as Al₂O₃ in water and the second solution was 20 wt. %aluminum as Al₂O₃ sodium aluminate in water. Upon completion of theaddition, the weight ratio of aluminum sulfate:aluminum sodium sulfatein the reactor was 5:3. The flow rates are adjusted during addition toprovide a pH of 7.6. When the 7.6 pH target is met, the aluminum sulfateaddition is terminated and the sodium aluminate addition is continueduntil a pH of 9.3 is reached. The sodium aluminate addition is thenterminated, and the reactor contents aged for 2 hours at 66° C. (150°F.) The precipitated product is then filtered, washed and spray dried at371° C. (700° F.) inlet temperature 135° C. (275° F.) outlet temperatureto form an aluminum powder which is sized to a particle size of 10-20microns. The resulting product is designated CAX-1. The propertiesthereof are summarized at Table 11 and FIG. 20. The data on CAX-1 inFIG. 20 is designated Run 61.

TABLE 11 RUN NO. 60 61 Sample # AX-1 CAX-1 TV @ 1750° F. wt. % 22.0 29.4SA m²/g 291 292 N₂PV (0.967 p/p^(°)) cc/g 1.16 0.94 DPI n/a 31 APS μ 9.815.9 Na₂O wt. % 0.41 0.03 SO₄ wt. % 0.04 0.82 Fe wt. % 0.05 0.01Mesopore Pore Mode Å 150 65.7 % increase in Mesopore Pore % 60 N/A Mode

As can be seen from Table 11 and FIG. 20, AX-1 (Run 60) and CAX-1 (Run61) have similar surface areas, but AX-1 has about 20 v% more porevolume than CAX-1 and the mesopore pore mode of AX-1 is about 150Angstroms compared to 50-70 Angstroms for CAX-1.

EXAMPLE 20

Part A

This example illustrates the preparation of a pre-impregnation of AX-1prior to extrusion.

13.6 kg (30 lbs.) OB of AX-1 alumina were mixed in an Eirich mixer with10.5 kg of city water, 6.2 kg of ammonium molybdate solution and 2.0 kgof commercial grade (15% Ni) nickel nitrate solution. The ammoniummolybdate solution was prepared by dissolving 2.2 kg of commercialammonium dimolybdate crystals in 4.0 kg of deionized water. The mix wasextruded in a 4″ Bonnot pilot plant extruder to form 0.04″ diameterextrudates using conventional extrusion conditions. The extrudates weredried at 121.1° C. (250° F.) for 4 hours and calcined at 648.9° C.(1200° F.) for 1 hour. The resulting extrudate is designated EMAX-1 (Run62).

Part B:

The pore property results of Part A of Example 20 were normalized to ametals free basis and the results designated as Run 63 . Samples arenormalized herein to a metals free basis in accordance with thefollowing Equation: $\begin{matrix}{{MFB} = \frac{(X)\quad (100)}{\left( {100 - W} \right)}} & \left( {{Equation}\quad 6} \right)\end{matrix}$

Wherein X is this pertinent pore property such as PV (in cc/g), or SA(m²/g)

W=the wt. % of catalytic promoter metal oxides such as Ni, Co. and Mooxide on the catalyst based on the wt. of porous constituents of thecatalyst. The weight of non-porous constituents, e.g., non-porousdiluents, of the catalyst extrudate are not included in the wt. %calculation and MFB=Metals Free Basis.

COMPARATIVE EXAMPLE 4

Part A:

Example 20 of Part A was repeated except that the AX-1 sample fromExample 19 was replaced with the CAX-1 sample of Comparative Example 3.The resulting extrudate product is designated EMCAX-1 (Run 68).

Part B:

The pore property results of Part A of Comparative Example 4 werenormalized to a metals free basis and the results designated Run 69.

Physical and compositional properties of the metal impregnated catalystsamples EMAX-1 and EMCAX-1 are provided at Table 12 and the mercury poresize distribution and other properties of these samples is provided atTables 13A and B.

A higher SiO₂ is also noted due to the nature of the dispersible claycontained in AX-1. A plot of the mercury pore size distribution of eachcatalyst is shown in FIG. 21.

Of particular note is that SA and TPV of both Run 62 and Run 68 aresimilar. but that the pore mode for Run 62 is 145 Å compared to only 65Å for Run 68. These modes are very close to those of the startingaluminas which is characteristic of the stabilizing effect ofpre-impregnated metals on the alumina properties. As can be further seenfrom Tables 13A and B, pore diameters have shifted from the <100 Å inRun 68 to the 100-250 Å region, and more predominantly to the 130-250 Åregion for Run 62. In spite of the shift and increase in pore modes thetotal surface area and total pore volume of Run 62 are similar to Run68.

TABLE 12 Metal Pre-Impregnated Extrudates Run No. 62 64 66 68 Sample IDEMAX-1 EMAX-2 EMAX-3 EMCAX-1 Alumina AX-1 AX-1 AX-1 + CAX-1 Type CAX-1 2parts + 1 part Catalyst Properties MoO₃ wt. % 14.1 14.9 14.1 13.6 NiOwt. % 3.1 3.5 3.1 3.3 SiO₂ wt. % 0.66 0.61 0.51 0.08 Na₂O wt. % 0.2 0.180.17 0.06 Fe wt. % 0.01 0.01 0.01 0.08 Particle mm 0.98 0.99 1.00 1.00Diameter CBD, lbs/ft³ 35.4 32.1 34.5 −36 MaxPack Crush lb/mm 2.9 2.5 2.01.7 Strength CBD = Compacted Bulk Density

EXAMPLE 21

Part A:

The alumina sample AX-1 prepared in accordance with Example 19 was usedto make a metal impregnated extrudate in accordance with Example 20,Part A, except that the mix contained 300 g more water in order toincrease the amount of porosity in pores greater than 250 Å in diameter.The resulting extrudates are designated EMAX-2 (Run 64).

Part B:

The pore property results of Part A of this Example were normalized to ametals free basis and the results designated Run 65 and reported atTables 13A and 13B.

TABLE 13A Total Pore Volume* RUN Ex or Comp<100Å >100Å >130Å >150Å >250 >500 >1200 NO. Sample Ex No cc/g ° ″ cc/g °″ cc/g ° ″ cc/g ° ″ cc/g ° ″ cc/g ° ″ cc/g ° ″ 62 EMAX -1 Ex20(a) 26 33.53 67 .42 53 .34 43 17 21 .10 13 .07 9 63 MFB-EMAX-1 Ex20(b) .31 32.9.64 67.1 .51 53.2 11 43 .21 21.5 .08 8.9 64 EMAX-2 Ex21(a) .26 29 .62 70.50 57 .43 49 .21 24 .13 15 .11 12 65 MFB-EMAX-2 Ex21(b) .32 29.5 .7670.5 61 56.8 .53 48.9 .26 23.9 .13 12.5 66 EMAX-3 Ex22(a) .36 40 54 6044 49 .38 42 25 28 .17 19 12 13 67 MFB-EMAX-3 Ex22(b) 4.3 40 65 60 .5348.9 .46 42.2 .30 27.8 .14 13.3 68 EMCAX-1 CEx4(a) 44 51 .38 44 .33 38.31 36 .27 31 .24 28 .21 24 69 MFB-EMCAX-1 CEx4(b) 53 53.7 .46 46.3 .4040.2 37 37.8 .32 32.9 .25 25.6 70 EAX-4 Ex23 22 27.2 .59 72.8 .44 53.924 29.6 .04 4.9 .02 2.5 0 0 71 EAX-5 Ex24(a) .24 27.6 .63 72.4 .48 55.2.32 36.8 .06 6.9 .03 3.4 .02 2.3 72 ECAX-2 CEx5 32 33.7 6.3 66.3 .3840.0 .28 29.5 .20 21.1 .17 17.9 .14 14.7 73 EMAX-5 Ex24(b) .11 15.1 6284.9 .52 71.2 43 58.9 0.5 6.8 .03 4.1 .02 2.7 74 EMAX-6 Ex25 .16 17.6.75 82.4 .59 64.8 50 54.9 .26 28.6 .16 17.6 .10 11.0 75 EMCAX-2 CEx6 1822.5 .62 77.5 0.42 52 .31 38.8 .18 22.5 .15 18.8 .12 15.0 Total PoreVolume* RUN Ex or Comp >1500 >4000 100-130Å 130-250Å NO. Sample Ex Nocc/b ° ″ cc/g cc/g ° ″ cc/g ° ″ 62 EMAX -1 Ex20(a) .06 7.6 0.3 .13 13.9.31 31.6 63 MFB-EMAX-1 Ex20(b) .07 7.6 64 EMAX-2 Ex21(a) .11 12 .04 .1513.6 .36 33 65 MFB-EMAX-2 Ex21(b) .13 12.5 66 EMAX-3 Ex22(a) .11 12 .04.12 11.1 .23 21.1 67 MFB-EMAX-3 Ex22(b) .13 12.2 68 EMCAX-1 CEx4(a) .2023 .15 69 MFB-EMCAX-1 CEx4(b) 24 24.4 70 EAX-4 Ex23 0 0 0 .15 18.9 .4049 71 EAX-5 Ex24(a) .01 1.1 .01 .15 17.2 .42 48.3 72 ECAX-2 CEx5 1.313.7 .06 25 26.3 .18 18.9 73 EMAX-5 Ex24(b) .02 2.7 .01 .10 13.7 .4764.4 74 EMAX-6 Ex25 .09 9.9 .02 .16 17.6 .33 36.3 75 EMCAX-2 CEx6 .1215.0 .04 0.20 25.5 0.24 29.5 *by Hg Porosimetry with Contact Angle =140°

TABLE 13B Pore SA TPV Run Ex or Comp Mode A m²/g cc/g No. Sample Ex No(dV/dlogD) (Hg) (Hg) 62 EMAX-1 Ex20(a) 148 288 0.86 63 MFB-EMAX-1Ex20(b) 148 348 .95 64 EMAX-2 Ex21(a) 135 290 .88 65 MFB-EMAX-2 Ex21(b)135 355 1.08 66 EMAX-3 Ex22(a) 119/63 312 .90 67 MFB-EMAX-3 Ex22(b)119/63 377 1.09 68 EMCAX-1 CEx4(a) 67 297 0.82 69 MFB-EMCAX-1 CEx4(b) 67357 .99 70 EAX-4 Ex23 148 212 .81 71 EAX-5 Ex24(a) 158 222 .87 72 ECAX-2CEx5 99 201 .95 73 EMAX-5 Ex24(b) 191 160 .73 74 EMAX-6 Ex25 115 180 .9175 EMCAX-2 CEx6 115 192 .80 MFB = Metals Free Basis

EXAMPLE 22

Part A

The catalyst was prepared in the same way as EMAX-1 (Run 62) except thatthe alumina source was a physical powder blend of 9.09 kg (20 pounds)original batch (OB) of AX-1 (Run 60) and 4.5 kg (10 pounds) OB of CAX-1(Run 61). The CAX-1 alumina was added to increase macroporosity(pores >250 Å) in the catalyst. The resulting product is designatedEMAX-3 (Run 66) and the properties thereof are summarized at Tables 12and 13A and B, and FIG. 21. As can be seen therefrom, the addition ofCAX-1 adds pores in <100 Angstrom region and the <250 region becomesbimodal.

Part B

The pore properties of the sample of Part A were normalized to a metalsfree basis and the results designated Run 67 and reported at Tables 13Aand B.

EXAMPLE 23

This example describes a procedure of making the alumina base (only) ofa catalyst that could be eventually finished into catalyst via a“post-impregnation” process. The base for post-impregnated catalysts isprepared by extruding/calcining the alumina in the absence of promotermetals (Ni and Mo in this case).

30 pounds OB of AX-1 alumina were mixed with 31 pounds of city water ina pilot scale Eirich mixer. The mix was extruded using a 4″ Bonnotextruder to form 0.04″ diameter extrudates. The extrudates were dried at121.1° C. (250° F.) for 4 hours and then calcined at 732.2° C. (1,350°F.) for 1 hour.

The resulting product is designated EAX-4 (Run 70) and the mercury poreproperties shown at Tables 13A and B.

COMPARATIVE EXAMPLE 5

Example 22 was repeated except that the starting alumina was CAX-1. Theresulting product is designated ECAX-2 (Run 72). The mercury poreproperties are shown at Tables 13A and B.

Comparing Runs 70 with 72, it can be seen that Run 70 has almost 70% ofthe TPV in the 100-250 Angstrom range, and the majority (49%) in the130-250 Angstrom range. It will be further noted that Run 72 shifts thepore mode of the starting CAX-1 alumina (Run 61) from 65 Angstroms to100 Angstroms in the extrudate. The same is not true of Run 70 (FIG. 22)versus AX-1 of Run 60 (FIG. 20) which both exhibit a pore mode at about145 Angstroms. Moreover, Run 70 exhibits about the same pore mode asRuns 62 and 64 (FIG. 21). Thus, it appears the AX-1 alumina of thepresent invention has the same pore mode whether pre- orpost-impregnated. It will be further noted that Run 70 has essentiallyno porosity >250 Angstroms unlike its pre-impregnated analog of Run 62.

EXAMPLE 24

Part A

Example 23 was repeated except that 14.5 kg (32 pounds) of water (1pound more than in Example 23) was employed in the mixture to increasetotal porosity in the pores >250 Angstroms. The resulting extrudate isdesignated EAX-5 (Run 71).

The compositional properties, particle diameter, and crush strength ofRuns 70 to 72 are summarized at Table 14, and the mercury poredistribution of the samples of Runs 70-72 are summarized at Tables 13Aand B. The mercury pore distribution of Runs 70-72 is also shown at FIG.22.

Part B

The EAX-5 (Run 71) metal free extrudate sample of Part A waspost-impregnated as follows:

313 g of ammonium molybdate solution adjusted to 5.2-5.4 pH was mixedwith 120 g of nickel nitrate. Water was added to make a total of 440 ccof solution. The entire solution was transferred onto 550 g of EAX-5base. Impregnation was done by incipient wetness technique in a plasticbag. The impregnated material was dried overnight at 121.1° C. (250° F.)and calcined at 537.8° C. (1,000° F.) for one hour. The resultingcatalyst is designated EMAX-5 (Run 73) the mercury pore properties ofwhich are shown at Tables 13A and B.

COMPARATIVE EXAMPLE 6

Example 24. Part B, was repeated except that the EAX-5 sample wasreplaced with the extrudate control sample.ECAX-2 of Run 72. Theresulting metals impregnated extrudate sample is designated EMCAX-2 (Run75) the mercury pore properties of which are shown at Tables 13A and B.

EXAMPLE 25

Example 22 was repeated except that the blend was composed of equalamounts of AX-1 and CAX-1 6.8 kg (15 pounds) each. The blend was mixedwith 31 pounds of water in an Eirich mixer, impregnated with nickel andmolybdenum using a metals solution prepared in accordance with Example24. Part B, except the total solution volume was 550 cc due to a higherpore volume of the present sample.

The resulting metal impregnated extrudate is designated EMAX-6 (Run 74),the mercury pore properties of which are shown at Tables 13A and B.

The compositional properties, particle diameter, bulk density, and crushstrength for Runs 73 to 75 are summarized at Table 15.

TABLE 14 Examples of Metals-Free Base Run No. 70 71 72 Sample ID EAX-4EAX-5 ECAX-2 Alumina Type AX-1 AX-1 CAX-1 Catalyst Properties MoO₃ wt. %Metals-Free NiO wt. % Metals-Free SiO₂ wt. % 0.2 0.2 1.01 Na₂O wt. %0.42 0.41 0.03 Fe wt. % 0.05 0.05 0.01 Particle Diameter mm 0.99 0.971.02 Crush Strength lb/mm 1.96 1.55 1.74

TABLE 15 Post-Impregnation Examples Run No. 73 74 75 Sample ID EMAX-5EMAX-6 EMCAX-2 Alumina Type AX-1 AX-1 + CAX-1 CAX-1 Equal Parts CatalystProperties MoO₃ wt. % 13.5 13.3 13.3 NiO wt. % 3.5 3.4 3.5 SiO₂ wt. %0.65 0.24 Na₂O wt. % 0.17 0.11 Fe wt. % 0.0 0.01 Particle Diameter mm0.99 0.99 CBD, MaxPack lb/cf 39.6 33.7 36.8 Crush Strength lb/mm 1.641.84

EXAMPLE 26

Vacuum tower bottoms (VTB) derived from arab medium crude oil having theproperties summarized at Table 16 was selected as the feed to a fixedbed resid hydrotreating pilot plant unit. The operating conditions ofthe pilot plant are summarized at Table 17.

The catalyst from Run 62 (EMAX-1) was placed in the pilot unit andtested as described below. The pilot unit has four independent reactorslocated in a common sandbath. The sandbath maintains the four reactorsat approximately the same temperature. Each reactor is loaded with 75 ccof the catalyst to be tested. Inert glass beads are loaded above andbelow the catalyst bed to preheat the reactants to the desiredconditions and to take up any additional space. Hydrogen and residfeedstock enter the bottom of the reactor and flow together up throughthe catalyst bed and out the top of the reactor. The products go into agas liquid separation vessel which is located downstream of the reactor.The gas products pass out of the system through a pressure control valvewhich is used to control the reactor pressure. The liquid products passfrom the separation vessel through a level control valve to the liquidproduct vessel which accumulates the product until it is removed fromthe system. The hydrogen flowrate to the reactor is controlled with amass flow controller. The resid feedrate to the reactor is controlledwith a feed pump. The temperature of the reactors are controlled bychanging the temperature of the sandbath.

The catalyst was tested at reference conditions: LHSV of 1.0 (75 cc/hrfeed and 75 cc of catalyst bed volume), reactor temperature of 426.7° C.(800° F.) and 2000 psig H₂ pressure. The hydrogen flowrate wasmaintained at 75 Normal Liters (NL)/hr (Note: NL is measured at 0° C.and 1 atmosphere pressure). These conditions produce about the samelevel of conversion as well as sulfur and Conradson carbon removal aswould be expected for the conventional catalysts in a commercialebullating bed hydrocracker. The percent conversion of materials boilingover 537.8° C. (1000° F.) to materials boiling under 537.8° C. wasmeasured as a function of time expressed as barrels of feed processedper pound of catalystloaded.

The results are shown at FIG. 23 and designated Run 76.

COMPARATIVE EXAMPLE 7

Example 26 was repeated except that the catalyst from Run 68 wasemployed in lieu of that from Run 62.

The conversion results are also summarized at FIG. 23 as Run 77. As canbe seen from FIG. 23, the AX-1 derived sample of Run 76 exhibits ahigher activity for cracking the high boiling (1000+° F.) resid materialto lighter products than the reference CAX-1 derived sample of Run 77.The data shown are corrected to the standard operating conditions toremove any fluctuations caused by changes in the actual operatingconditions. The AX-1 derived catalyst of Run 76 also has activityadvantages for saturation (product API increase), desulfurization andConradson carbon removal. It is theorized that the higher cracking andhydro-activity of this catalyst is due to the modified pore sizedistribution, and perhaps the chemical composition of base due to theAX-1 starting materials.

Sediment and metals removal for Run 76 are slightly inferior to thecontrol of Run 77. Sediment is expected to increase at higher residconversion. The Run 76 sample also has lower porosity in the macrorange, which may also be affecting sediment and metals performance onthis feed.

TABLE 16 Feedstock Properties Feedstock Arabian Medium Vacuum Resid IDNumber F94-71 F98-559 AP1 @ 60° F. 4.87 5.60 S.G. @ 60° F. 1.0376 1.0321Sulfur wt. % 5.88 4.72 Total Nitrogen, wt. % 0.41 0.34 Basic Nitrogen,wt. % 0.043 0.12 Conradson Carbon, wt. % 23.2 26 Pentane Insoluble, wt.% 27.0 22.9 Toluene Insoluble, wt. % 0.06 0.16 Metals (ppm) Ni 36.8 29.4V 118.3 103.3 Fe 7 43.9 Zn 2.1 2 Ca 21 7 Na 5.6 21 K 1.4 1.1Distillation: LV % > 1000° F. 87 97

TABLE 17 Operating Conditions of Pilot Plant Feedstock: Arabian Med VTBPressure: 2000 psig Rx Temp: 790-800° F. (near isothermal) Feedrate: 75cc/hr H₂ Once Thru: 75 NL/hr (6000 SCFB) Run Length: 3 weeks (about 2.0bbl/lb) Upflow Regime Catalyst Loading: 75 cc LHSV (Catalyst Basis)Glass Bead Section Provides reactor space without catalyst Simulatescommercial cat/thermal space ratios

EXAMPLE 27

Example 24 was repeated except the catalyst from Run 64 (EMAX-2)replaced the catalyst of the reference example and the feedstock was analternate Arab medium Vacuum Resid, the properties for which aresummarized at Table 16. The results are grouped as Run 78 and theconversion performance is summarized at FIG. 24.

EXAMPLE 28

Example 27 was repeated using the catalyst of Run 66 (EMAX-3) and theresults grouped as Run 79 and depicted at FIG. 24.

COMPARATIVE EXAMPLE 8

Example 27 was repeated using the control catalyst of Run 68 (EMCAX-1).The results are grouped as Run 80 and depicted at FIG. 24.

As can be seen from FIG. 24, Runs 78 and 79 are superior to the controlin conversion.

Moreover, in respect to:

(a) Total Liquid Product API, the control was inferior to Run 79 butsuperior to Run 78;

(b) Sulfur Reduction—the control was inferior to Run 79 but superior toRun 78;

(c) wt. % Conradson Carbon Residue (CCR) Reduction—the control wasinferior to Run 79 but superior to Run 78;

(d) Sediment Reduction—the control was superior to Runs 78 and 79, withRun 79 being better than Run 78;

(e) Vanadium Reduction—the control was superior to Runs 78 and 79, withRun 79 being better than Run 78;

(f) Nickel Reduction—the control was inferior to Run 79 but superior toRun 78.

Note that the CCR is the leftover carbonaceous material after all of thelighter hydrocarbons are boiled away. It is measured by a standarddestructive distillation test (ASTM (D-189). The test is run on the feedand on the products. The difference between the two numbers is the CCRreduction.

The principles, preferred embodiments, and modes of operation of thepresent invention have been described in the foregoing specification.The invention which is intended to be protected herein, however, is notto be construed as limited to the particular forms disclosed, sincethese are to be regarded as illustrative rather than restrictive.Variations and changes may be made by those skilled in the art, withoutdeparting from the spirit of the invention.

What is claimed is:
 1. In a process for the hydroprocessing of petroleumfeedstock wherein said feedstock is contacted with hydrogen underpressure in the presence of a supported hydroprocessing catalyst, theimprovement comprising utilizing porous agglomerate particles as thesupport for the supported catalyst wherein said porous agglomerateparticles comprise constituent composite particles of a swellable claycomponent intimately dispersed within an aluminum oxide componentwherein: (A) the agglomerate particle size is from about 0.5 to about 5mm; (B) the aluminum oxide component comprises at least 75 wt. %alumina, at least 3.75 wt. % of which aluminum oxide component is in theform of crystalline boehmite, gamma alumina derived from the crystallineboehmite, or mixtures thereof; and (C) the swellable clay component ispresent within the aluminum oxide component at an amount (i) of lessthan 10 wt. %, based on the combined weight of the aluminum oxide andswellable clay components, and (ii) effective to increase at least oneof the hydrothermal stability, mercury pore volume, and the mercurymesopore pore mode of the agglomerate particles relative to thecorresponding hydrothermal stability, pore volume and mesopore pore modeof the agglomerate particles in the absence of the swellable clay. 2.The process of claim 1 wherein the support agglomerate particlespossess: (i) a specific surface area of at least about 200 m²/g; (ii) amesopore mercury pore mode of from about 60 to about 400 Angstroms; and(iii) a total mercury pore volume of from about 0.5 to about 1.8 cc/g.3. The process of claim 1 wherein in the porous agglomerate particles,the aluminum oxide component comprises at least 90 wt. % rehydratedactive alumina at least 7.5% of which aluminum oxide component is in theform of crystalline boehmite, gamma alumina derived from the crystallineboehmite, or mixtures thereof, and the swellable clay component ispresent in the agglomerate constituent particles at from about 1 toabout 8 wt. %, based on the combined weight of the swellable claycomponent and aluminum oxide component.
 4. The process of claim 1wherein in the porous agglomerate particles, the swellable claycomponent comprises smectite clay.
 5. The process of claim 4 wherein inthe porous agglomerate particles, the smectite clay is selected from thegroup consisting of montmorillonite, hectorite, and saponite.
 6. Theprocess of claim 1 wherein in the porous agglomerate particles, thesmectite is a natural or synthetic hectorite.
 7. The process of claim 6wherein in the porous agglomerate particles, the smectite is a synthetichectorite.
 8. The process of claim 7 wherein in the porous agglomerateparticles, the swellable clay component is present therein at from about2 to about 7 wt. % based on the combined weight of the aluminum oxideand swellable clay components.
 9. The process of claim 1 wherein theporous agglomerate particles when calcined at 537.8° C. for 2 hours,have a mesopore mercury pore mode of from about 70 to about 250Angstroms, a mercury surface area of from about 200 to about 350 m²/g,and a total mercury pore volume of from about 0.6 to about 1.5 cc/g. 10.The process of claim 1 wherein the porous agglomerate particlesadditionally contain from about 2 to about 10 wt. % silicate based onthe combined weight of silicate, aluminum oxide component, and swellableclay component, intimately dispersed within the constituent particles.11. The process of claim 1 wherein the catalyst supported on theagglomerate particles is at least one hydrogenation component of a metalhaving hydrogenation activity selected from the group consisting ofGroup VIII and Group VIA metals of the Periodic Table.
 12. The processof claim 1 which is conducted in at least one ebullating bed reactor.